Windowzoo is one of the first community art projects worldwide.

The project turns everyone into an artist and every location into an exhibition space. Having found its origins in streetart, windowzoo has gone further and generated a new, non-destructive kind of urban landscape intervention. The context of an installation is equally important as the installation itself. The work installed might not be from the artist installing it and the photograph that makes it to the website might be from yet another person. The digital platform connects the installations across continents, time and space. Multiple layers of interaction combined with growing global appearance and disappearance.
http://windowzoo.com/