Isocity

Here's the project very similar to MrWong's SoupPartments. At Isocity everybody can upload their building (of course it needs to be pixel art and fit into given template).
There are some very sweet pixel art houses already - it's worth to check it out and it's worth to be a part of it;).
Check out the Isocity at http://www.kennethfejer.com/isocity/.