If you are the kind of person who would live to roam the world, and are interested in doing it at a minimal cost, this is the site for you. Here you will find people all over the world lending you a spare couch in their homes to sleep a night in when you visit their city. Its a great way to interact with locals who will also act as your guides when you visit them. Check it out

http://www.couchsurfing.org/