Airbnb - Book unique places to stay and things to do.
Fat Lama - Borrow stuff you need. Lend stuff you don't
June Homes - Rentals Redefined
Idle - Rent Any Thing - A Peer-to-Peer Renting Community for Idle Goods
HomeAway - With HomeAway you can respond to inquiries, manage the property calendar, send quotes and payment...
Daylui.com - Daylui is an "Airbnb for everyhing else".