Lately I have found that age specific tours are all the rage. One of the most prominent travel specialists is Contiki tours. Founded in 1962 Contiki caters to the 18-35 age group, and offers travel options to the following areas: Europe, America, Australia, Russia, Egypt, New Zealand, and the Far East. The company offers three price ranges ranging from College Student Poor to Former Investment Banker Rich. Depending on the scheme you choose you will either be bunking in Tents, Hostiles, or 4 star hotels. Most importantly, however, the tours offer a great way (and cheap if you are in fact College Student Poor like me) to see the world, and see it with people of your own age (meaning less museums and more clubbing perhaps?)
You can find out more about Contiki Travel here.