What is wikimapia ?

Well it seem's appropriate to quote Wikipedia...
"WikiMapia is an 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.^[2] It is one of the top 1000 websites visited,^[3] and has over 5 million places marked.^[4] It was created by Alexandre Koriakine and Evgeniy Saveliev, and was launched on May 24, 2006 with the aim of "describing the whole planet Earth".

It is a great site, where you can tag anywhere in the world* with a box and some details about the location. The site is geared towards commercial enterprises but anyone can tag anything (within reason). You can tag your house, school, gym, place of work whatever you like.

* Image resolution will vary