If you are suddenly surrounded by a crowd, its only purpose can be to distract your attention from pickpockets at work. These calls are free of charge. You need a valid passport to enter the Czech Republic. Citizens of most European countries, U.S.A., Canada, Israel, and some other countries do not need visa for short term visits. Do not change money with strangers on the street, otherwise you will be cheated.
More information is available at Czech airlines homepage .
Among U.S.A. carriers, Delta has a flight to Prague, with a stop in Amsterdam. They operate vans from the airport for a fixed price 360 Kc for a company up to 4 people to any place in the city center, including the hotels and the conference location. You find their white vans and cars directly at the sidewalk in front of the arrival hall of the airport, the ride takes about 30-45 minutes. You can also order a return trip to the airport at phone number 20114286 or 20114296. See the maps and public transportation below.