We placed a free-form text canvas on top of Google maps and added geolocation to see what happens when we combined online chat with the pre-existing relationships that are inherent to physical location and real-world places.
Initially, we only allowed New York. We've removed that restriction, but haven't really been promoting it, so the rest of the world is pretty blank.
Check it out: WrittenWorld.org
I'm rewriting this project from scratch for my ITP masters thesis. I'll be adding features like zooming, location search, subworlds, and realtime cursors.