Global Entry Program
If you travel frequently ot the United States by air, you may want to consider enrolling in the Global Entry Program offered by the U.S. Customs and Border Protection Service (www.cbp.gov) which will speed your entry at many major airports.
The program is good for five years and costs $100. If you qualify, you can go to an electronic kiosk rather than standing in often very long lines after a long flight from abroad. U.S. or Canadian citizens also have access to the Transportation Security Agency's pre-check program, which makes security clearance at the airport a lot easier.
I benefitted from this pre-check program on a recent trip (I guess I looked harmless) and it was a big help. You don't need to remove liquids or computers from your carry-on luggage, or to take off your shoes. This can be a significant advantage when you have a short connection time between planes.
In order to qualify for Global Entry, you must pass a rigourous background check and be interviewed at a location in the U.S. Most interview locations are at airports, but there is also one downtown in Washington, DC. You do not need to be a U.S. citizen.
Check out an article on www.smartertravel.com by Caroline Morse that appeared on Jan. 3 of this year on the pros and cons of this program. One of the cons is that you need to pay upfront, and if you don't qualify your fee is not refunded. Also, your status can be revoked for certain violations of customs laws such as not declaring that you are carrying prescription drugs or currency totalling more than $10,000 U.S.