WikiMapia

Wikimapia is an online editable map - you can describe any place on Earth. Or just surf the map discovering tons of already marked places.

WikiMapia is a privately owned, online map and satellite imaging resource that combines Google Maps with a wiki system, allowing users to add information, in the form of a note, to any location on Earth. Users may currently use this information for free. Inspired by the success of Google Maps and Wikipedia, two Russian Internet entrepreneurs Alexandre Koriakine and Evgeniy Saveliev launched the website on May 24, 2006. 

Its aim is to "describe the whole world". It now has over 15,000,000 places marked. Although registration is not required to edit or add to WikiMapia, over 1,100,000 users from around the world currently are registered. All content uploaded by users is currently made available under Creative Commons license for non-commercial use through Wikimapia API. Approximately 1,000 new users register everyday.