Overnight - Book a last minute room with locals, in seconds.
Postcrossing - A postcard exchange project that invites everyone to send and receive postcards from random places in the world. For free!
Cool Cousin - Shaking up the travel world with good old human connection
BookCrossing.com - It's the World's Library. It's a smart social networking site.
Airbnb - Book unique places to stay and things to do.
InterPals - InterPals is a friendly community of over 5 million friends, language learners, travelers and penpals.