MyPostcard - Send real photo postcards and greeting cards - worldwide, from any place to anywhere.
BeWelcome - Open your door to the world!
Postsnap - Postsnap's iPhone app is the best, free postcard creator. Make & send real printed postcards, greeting cards, invitations and announcement cards using your own photos.
Trustroots - Travellers community for sharing, hosting and getting people together.
YourTravelRoute - Create manually or automatic travel routes according your desires. After this, plan how to transfer between the destination and get planning help.
Hospitality Club - Free network of people around the world who offer free accommodation, advice and help when they are traveling - hospitality exchange. Free membership.