AirBnB.com offer peer to peer rental for visitors. Normal users can place their apartment , house or single room for rent to strangers to make some extra money. AirBnB.com has increased in popularity and has more than $2 Billion valuation by end of 2012. If you want to create a website similar to AirBnb you can iScripts ReserveLogic which is an airbnb clone software. This open source php reservation software can support unlimited locations and properties.
Checkout https://www.iscripts.com/reservelogic for more details