VisasIf you're willing to give visa officials a bribe (officially called "expedited service"; perfectly legal, of course) then most countries will be happy to issue you a visa in a reasonable amount of time, at most a few weeks. The United States is different. If you need a visa, and you don't have one yet, you're screwed. If you spend weeks calling the United States visa officials and repeatedly explaining to them that time is running out before a flight on the 15th, then at best you'll convince them to issue you a visa on, say, the 20th.
If your country is on very good terms with the United States, you can enter the United States on a "visa waiver"; but you must fill out a free online form in advance. The official recommendation is to fill out this form at least 72 hours in advance. This is not a hard deadline, and if you fill out the form at the departure airport then it might be approved instantly; but it might not, and you might be denied boarding.
Let's say you get past these obstacles and arrive in the United States. Expect very long, very slow lines at immigration. The official United States policy is that paying an idle immigration officer is a disaster, while having the tired and hungry wait on line for an hour or two is just fine, as long as they're foreigners. Eventually you'll reach an immigration officer and, in exchange for being allowed to enter the country, you'll turn over the usual pile of information, including biometrics collected at the immigration booth: photo, 10 fingerprints, and (for men) dick-size measurements. Don't panic if the immigration officer asks you questions like "Why do you have a Chinese visa in your passport?"; simply answer the questions, honestly and politely.
After immigration you'll find an empty luggage belt. You might be worried that someone walked off with your luggage a long time ago. Relax: the airline won't have bothered delivering your luggage yet. You'll now wait for your luggage while hoping that the drug-sniffing dogs don't notice the smell of airline food on your breath. Finally you'll pass through some doors into the land of hope and freedom.
Special note regarding mobile phones: Most (all?) American airports will allow you to use your phone after the plane touches down. However, you're not allowed to touch the phone after you leave the plane, or while you're on line at immigration, or while you're waiting for your luggage.
Special note regarding transfers: If you fly internationally to the United States and then connect to another flight, you will have to clear immigration and customs at the first airport, and you will have to pick up your bag at the first airport (after immigration and before customs), even if the bag has been checked through to the second airport. Furthermore, if you fly to Canada and then connect to a flight to the United States, you will have to clear United States immigration at the Canadian airport, pick up your bag, clear United States customs, and re-check your bag, before boarding the flight to the United States.
VersionThis is version 2010.08.12 of the visas.html web page.