Tinspot

This is one of the coolest sites I've come across in a while. See below for its own description:

Wikipedia Home Page

Wikipedia is a multilingual Web-based free-content encyclopedia. It exists as a wiki, a type of website that allows visitors to edit its content; the word Wikipedia itself is a portmanteau of wiki and encyclopedia. Wikipedia is written collaboratively by volunteers, allowing most articles to be changed by anyone with access to a computer, web browser and Internet connection. The project began on January 15, 2001 as a complement to the expert-written (and now defunct) Nupedia, and is now operated by the non-profit Wikimedia Foundation. Wikipedia has more than 3,800,000 articles in many languages, including more than 1,000,000 in the English-language version. Since its inception, Wikipedia has steadily risen in popularity[2] and has spawned several sister projects. Editors are required to uphold a policy of "neutral point of view", under which notable perspectives are summarized without an attempt to determine an objective truth.