There are a couple websites which allow you to design your perfect trip. This is helpful if you don’t want the extra expense of a travel agent.
The first one is Opentrips, a UK site which features designing your own trips. You can then invite people with like interests (friends or strangers) to join you. As of this writing, their homepage features trips such as “Write a cookbook in Italy’s Cilentro region” for foodies, “Cross the Alps! On your roadbike! No bags!” for the adventuresome. Many of these trips seem to center around food in different countries. Where would you like to go?
Another similar site is Tripobox. This is for you to design a trip for a group of your friends. You browse the hotel, restaurant, and activity offers in certain cities such as Berlin, Miami, Chicago (they are working on more). Add your favorite offers and plan your trips.