How is the United States different from other countries?
United Kingdom (which colonized        the US, and thus from which the tradition was adopted)
the Philippines (which the US        colonized)
the Federated States of Micronesia        (which used to be a territory of the US)
and Mexico (which borders the        US, and has a constitution heavily derived from the US one)
The US cabinet member responsible      for financial affairs is called the "Secretary of the Treasury" and leads the "Department of the Treasury." Most other nations      call their equivalent official the "Minister of Finance" and their department the "Department of Finance."
The US cabinet member responsible      for international diplomacy is called the "Secretary of State" and leads the "Department of State." Most other nations call      their equivalent official the "Minister of Foreign Affairs " and their department the "Department of Foreign Affairs." The title "Secretary of State" is a British term, and is used in      UK and some other Commonwealth nations. In the UK, every cabinet secretary      is formally called the "Secretary of State" as their full formal      title, for example the "Secretary of State for Education" or "Secretary      of State for Foreign Affairs." In casual language they are just referred      to as the "Education Secretary" etc, however.
It's interesting to note that in      the foreign language press American cabinet secretaries are usually referred      to as "ministers."
The Central      Bank
The central bank of the United      States, which is the organ of government responsible for federal monetary      policy, is known as the Federal Reserve of the United States. Most      other countries call their central bank simply "The Bank of [Country]" for example, "The Bank of England," or "The Bank of Italy." It should be noted, however, that the title "Federal Reserve" was      not the first choice, and was simply a name settled on after a lot of trial      and error with creating a working central bank. Prior to the Federal Reserve's      creation in 1916, the US central bank was called:
The First Bank of the United        States (1791-1811)
The Second Bank of the United        States (1816-1836)
The present head of United States      central bank is known as the Chairman of the Board of Governors. In      most other countries this official goes by the title of "Governor of      the Bank." In the US, however, every member of the Federal Reserve board of directors is given the title of "Governor."
The Electoral      College
Almost all countries in the world      with an executive, decision-making president allow the voters to elect him      or her directly, in an open, nation-wide election. This happens in the US      as well, of course, but the American system is distinct because of the presence      of the United States Electoral College.
The American electoral college      is the closest thing to an American parliament, in the sense that it selects      the head of government in a similar manner most parliaments select      their nation's prime minister. Each state elects a certain number of members      to the College, and the members assemble and collectively vote to choose the      President of the United States. Of course, nowadays this is just a huge formality.      They no longer even put the names of Electoral College candidates on the US      ballots anymore. Americans just vote for their president, and the party whose      candidate gets the most votes sends some figurehead delegates to symbolically      cast their votes for the same person.
What makes the College controversial      is the fact that there is always a narrow possibility that the formalities      do not go quite as planned. Because the electoral college is a "first-past-the-post" state-based representative body, it is possible for a candidate to win the most     seats despite winning only a minority of the popular vote. This is what happened      in the 2000 election, when George W. Bush won the most seats but Al Gore got      more of the popular vote.
Anyway, the point is, no other      country with a directly elected president has to go through such shenanigans.      In countries like France, Finland, Ireland, and all of South America, the      president is chosen solely on the basis of whoever wins the largest percentage      of the popular vote, with no middleman.
The closest equivalent occurs in      some countries with figurehead presidents, like India, Germany, and Israel.      In those cases the presidents are elected by the national parliament (sometimes      along with state legislatures). But since their presidents are largely powerless      nobodies, this is not of much practical relevance to the government.
Acting      / interim presidents
Political leadership in the United      States has been remarkably stable over the years, mostly because the US Presidency      is such a well-designed and stable institution. Once a president is elected,      he's quite hard to get rid of until the next scheduled election rolls around.      Impeachment is very complicated and has never been successfully attempted, and      other than that, Congress and the cabinet don't really have many tricks      at their disposal to depose the Head of State or force an emergency election.      Of the 43 American presidents, only nine have not served at least one full      term — that is, at least four years in office — and only one has resigned. That's almost an 80% success rate.
Because of the rigidly defined      terms and set election dates, there have not been very many "brief" presidencies.      Only two presidents served for less than a year, and that's because they both      died in office. Most other countries have far more leaders that served for      such brief periods, especially in the 20th Century. In fact, when you look      at many other official lists of national leaders, you often have to outright      ignore half of them, because they're either "acting" or "interim" or "caretakers" or what have you. To put it another way, every US      president has an official oil portrait hanging in the White House. In many      other countries, some presidents are considered insignificant enough to skip,      because though they may have held the office briefly for some reason, "they      don't really count."
The United States constitution      specifically allows for someone to "act" as President, during times      in which the current present is incapacitated or otherwise unable to serve      for a prolonged amount of time. Former Vice President Cheney and former Vice President      Bush both served as acting president during their time in office, but in both      cases they only held the position for less than a day.
There is no constitutional mechanism      to allow for an explicitly "interim" president, but theoretically      it could still happen. Any non-vice president (ie: a house speaker or cabinet secretary) who automatically ascends to the presidency someday      will likely be regarded as an interim American leader, because in all likelihood      he won't have a long-term interest in keeping in the job. Gerald Ford probably      would be considered an interim president had he not made a last-minute decision      to run for office in 1974.
NATION
Landmass
In 1959 Alaska became America's      49th state. Since then, the borders of the United States have been quite      unusual. While the American "mainland" remains one, giant cohesive     blob of land from California to New York, there is also a large blob of land      up north, bordering the nation of Canada and completely geographically isolated      from the rest of the 50 states. Geographers call areas like Alaska "non-contiguous      exclaves" and very few countries have such territories as part of their      borders.
Non-contiguous exclaves have historically      tended to be invasions waiting to happen. After the first World War Poland      was given a corridor of land which split Germany into two pieces. The Germans      then invaded Poland to rectify the situation, and I forget what happened next.
When Pakistan separated from India      in 1947 the new country consisted of two parts, "West" Pakistan,      and the much smaller province of "East" Pakistan. East Pakistan      was entirely landlocked by India, and as a result when the East Pakistanis      started pressing for independence, the Indian army invaded to help the province      separate. Today it's the country of Bangladesh.
Four other countries currently      have broken-borders like the US. They are:
Russia- the province        of Kaliningrad has a full three countries between it and the Russian mainland.
East Timor-        the East Timorese district of Oecussi is an exclave within the Indonesian        half of the Timor island.
Angola- the province        of Cabinda is landlocked within the borders of the Republic of Congo.
Azerbaijan-        a corridor of Armenian territory splits the territory of Nakhichevan from        the Azerbaijan mainland.
I doubt the Canadians will ever      invade Alaska, but I must say, I have heard a lot of grumblings over the years      about how the state "should be ours...."
The US State of Hawaii is also      a bit unusual, but overall it's far less of an anomoly, as lots of countries      have scattered island territories and possessions.
The Name
In the 2002 French film In Praise      Of Love at one point a character rants that the United States of America      is a country without a "real name." After all, the US is not the      only country in "America," he notes. Technically all the citizens      of all the countries in North and South America are "Americans" in some manner. Likewise, for citizens of the USA to go around calling their      country "the United States" makes little sense, as several other      countries use "the United States" in their full titles as well — consider "the United States of Mexico" or "the United States      of Brazil." In fact, one could just as accurately describe Brazil as      being "the United States of America" with this logic.
This is something of a semantics      game, but it is a valid observation. There are very few countries in the world      with a name as vague as the USA's. The United States never did create a new      nationality for itself. Instead they just hijacked the term "American" for this purpose, a name which had always been (and to some extent still is)      a very broad geographic description. Think of the Organization of American States, for instance. When you visit Latin American countries      they often bitch about this matter, and refuse to call people from the US "Americans" out of protest, instead calling them things like "North      Americans" or "United Statesians."
Countries with similarly vague      names include the Republic of South Africa, the Central African      Republic, and the United Arab Emirates. Like the US, these countries      are named after political/geographic entities, and fail to create a specific      nationality for their people as a result. One might include the United      Kingdom in the list as well, but to be fair the country's full name is      actually The United Kingdom of Great Britain and Northern Ireland.
The Capital      District
In most countries, the capital      city is just that — a city that also happens to be the capital. But in the      United States the situation is a bit weirder. The city of Washington is not      part of any state in the union, rather it is the only city in a specially-created "District of Columbia," which is a unique political entity unto itself. The logic was      that this was supposed to give the capital a sort of neutral status, because      it would not "belong" to any one state.
Nowadays a lot of people question      this concept, however. The half-million residents of Washington, for example, largely get      screwed by the deal. Since they do not legally live in any state they do not get      to elect any members of Congress (instead they get to elect one hack "delegate" who has no voting powers, and can only watch).They still get taxed and governed      by the federal government though, which has prompted them to bring back "no      taxation without representation!" as a rebellious rallying cry.
Only a few countries have copied      the idea of creating a federal district for their capital city:
Country
Capital District
Yes
These cities share some of DC's      problems, in that many of their local concerns are jointly managed by the      federal government and their own weak, elected municipal (or in the Indian      and Australian cases, state) style government. As you can see from the chart      above, however, DC is the only capital district where citizens are not given      any voting members in the national legislature.
SYMBOLS
Coat of      Arms
The United States lacks a formal      coat of arms, which is unusual for a western nation (but increasingly less      unusual, globally). The "Great Seal of the United States" is most      often used as an equivalent of a coat of arms when necessary, such as on the      cover of US passports.
National      Anthem
The American national anthem, the Star-Spangled Banner, is somewhat unusual by today's standards      in that it does not explicitly mention the "United States" or "America" anywhere in the lyrics. Most contemporary anthems do mention the country name,      but this is largely because most nations are young, and only wrote their anthems      in the last few decades. Older countries tend to have more historical anthems      that don't conform to the sort of "Oh, Country X, how we love thee" style that is now so prevalent.
Along with the US, other notable      countries that don't mention the country's name anywhere in the anthem include      the United Kingdom, Japan, Sweden, Spain, and Holland.
Official      Language
Though most Americans speak English      as their sole language, the American government in its long history has never      bothered to make English the official language of the country. Almost all      countries in the world have at least one official language, which in turn      serves as the language the government is mandated to provide services to its      citizens in. In the US, by contrast, the federal government will provide various      services in dozens of different languages, should they be requested.
The only other countries without      an official language are the UK, Australia, and Sweden.
Abstract      noun parties
America's two major political parties      are named after abstract nouns, and not specific ideologies. The Republican      Party is not called the "Conservative Party" for example, nor are      the Democrats called the "Liberal Party." Among mature democracies      this is a bit unusual, as most countries generally give their parties ideological      names, using terms like "liberal" "conservative" and "socialist" to indicate to voters where they stand.
The reason why the two main parties      in the US lack such qualifiers in their names is basically because they are      very old. They originally arose as catch-all coalition parties in the early      19th Century, when partisanship was more about strategy and simply winning      elections than conforming to any consistant set of ideological values. Most      political parties elsewhere in the world arose much later, however, often      in the post WWI-ea. At that time the polarization between liberals, conservatives,      etc was very intense, so it only made political sense to explicitly ally with      one side over the other.
Here are the main parties in some      of the world's main western democracies, it's usually pretty easy to tell      where they stand on the issues from their names:
Country
Social        Democrats
Moderate Coalition        Party
My suggestion is for the Republicans      to switch their name to "Party for a Conservative Republic" and      the Democrats can be the "Liberal-Democratic Party."
FOREIGN      POLICY
Nucelar      war
The United States is the only country      in the world that has used nuclear weapons for war purposes. Other countries      have developed nukes and blown them up for tests, but the bombings of Hiroshima      and Nagasaki during World War II remain the only instances of such weapons      actually being used against people.
Treaties
As many internationalists in both      the US and elsewhere never tire of pointing out, the government United States      often takes radically un-mainstream positions when it comes to ratifying international      treaties.
The two most glaring examples:
The United States is the only        country in the world that has not ratified the the Convention        on the Rights of the Child
The United States is one of        10 countries that has not ratified the Convention on the Elimination        of All Forms of Discrimination Against Women, and the only western nation        to not do so.
Things      that used to be unusual, but less so now
Presidency
The United States was the first      country to use the title of "President" for its head of state.      Now the majority of the world's countries use the title. Indeed, every      single republic in the world uses the name, even dictatorships. For a      while other countries tried using titles like "Director of the Republic" or simply "Head of State of the Republic" but now unless a country      has a king, it will have a president of some form.
Money      color
For a long time American currency      was known for only appearing in one color- green. Most other countries color-code      different denominations, or simply use money that features multiple colors      on individual bills. The greenness of American money has its roots in the      19th Century. At the time green dye was rare, and thus considered difficult      for counterfeiters to obtain. This bit of American uniqueness is now slowly      being phased out, however, as new US bills introduced in the early 2000's      now include multi-colored inks to help differentiate bills.
Decimalized      currency
Today, most of us take the existence      of decimalized currency for granted. That is to say, a currency in which 100      somethings (say, cents) add up to make a larger thing (say, a dollar). This      was not always the case though. Many countries originally had currencies which      used bizarre and arbitrary fractions as their basis. The English Pound was      the most infamous (and long-lived) example. Unlike today, where one pound      is worth 100 pence, until 1971 one pound was worth 20 shillings, with each      shilling being worth 12 pence (and each pence being two half-pence). The numbers      were rather arbitrary and confusing, hence why they were changed.
It's debated as to whether or not      the US was the first country to introduce decimalized currency; some      accounts give Russia credit with this. Regardless, the United States was certainly one of the first nations to do so, and helped popularize the practice.      Thomas Jefferson had been a big proponent of decimalization , and on his urging      the US dollar was decimalized in 1792. Today every country except Mauritania,      Japan, and Madagascar use the American-style 100 small = 1 large formula for      their currency.
Metric      System
Officially, the United States is      one of only three countries (Liberia and Burma being the other two) that has      not officially switched to the metric system. The US uses the "customary      system" which is also known as the "English" or "Imperial" system, because it has its roots in the UK. Of course, Americans are not simply      backwater kooks stubbornly clinging to an archaic system the rest of the planet      has completely discarded. The custom/imperial system actually continues to      thrive in defacto use all over the world, as in many cases countries only      formally adopted the metric system in the last 20 years.
Contrary to popular misconception,      however, the United States Federal government is officially pro-Metric,      and it is still official US policy to eventually switch. Implementation of the system has been at a snail's pace, however.
Consumer products in the United      States are labeled in metric, and American scientists no longer use the imperial      system in research. Overall, America has made considerable progress in making      Metric volume and distance measurements fairly mainstream.
The Anglican      Church
39 countries in the world are home      to a branch of the Anglican Church. Unsurprisingly, almost all of them are      countries with a history of colonization by the British Empire.
Some find it unusual that the US      branch of the church uses the title "Episcopalian" instead      of "Anglican" to describe itself. The reasons for this originally      stemmed from the aftermath of the Revolution, in which the American branch      of the church aggressively sought to separate itself from the authority of      London. Nowadays, all Anglican churches, or "provinces" as they      are known, are independent from the authority of London, and are only allied      to one another in a symbolic commonwealth. Titles wise, the US church is not      that distinct as we can see from this chart:
NAMES OF ANGLICAN CHURCHES AROUND      THE WORLD
"The Anglican Church of..."