MakeUseOf.com:

Flippa is a web service that acts as an online marketplace for buying and selling entire websites. The site is not new, it is actually redesigned and renamed version of a well known website auction section on a SitePoint.com.

You have to be registered before you can buy or sell websites. While buying, searching and browsing website listings are open to everyone, fees apply to selling websites.

Users may browse website listings by categories such as featured listings, latest auctions, latest private sales, ending soon and just sold.

Photo by Flippa.