BeWelcome - Open your door to the world!
Trustroots - Travellers community for sharing, hosting and getting people together.
Worldpackers - Exchange your skills for accommodation
Couchsurfing - CouchSurfing is your ticket to explore the world -- from the road or from your own home.
relaxed.com - its a travel website community and app for travel enthusiasts. It includes couchsurfing, Housesitting, Vacation Rentals, Work Abroad and many more travel modalities. it has travel forums, groups, news feed, galleries and travel experiences offers
FairBnB - A smart and fair solution for community powered tourism.