How to get around in the US Greyhound and much better: Amtrak

Airline companies in europe : Ryanair , Buzz , Go

Renting cars: HolidayAutos

Airline companies in the US : Southwest airlines

Travel overland , STA , opodo or FollowMe for trips from Germany

Orbitz , Kayak , Expedia , or Travelocity for trips in the US

General information at Lonely Planet

Bahnauskunft
Conversion rates for currencies.