Best of the Web - Collaborative Dungeons and worlds

MSJX has a a couple of post called CollaboDungeon 01! and CollaboDungeon 02 in which he provides a map and challenges/allows others to populate it. I really like this idea as it is nice to see how different folks might handle similar problems/challenges in the map. With the repetition of room descriptions that is likely to happen a GM could populate the dungeon and then restock it for an adventure a  year later. I also like the size of the dungeons so far, allowing a GM to make them stand-alone or sub-levels in a dungeon.

Wanderer Bill has a post called A free and open source setting for role playing games? in which he postulates a true collaborative creation of a setting with rules folks have to follow. It is an interesting idea, Tenkar did something similar with Tenkar's Landing Crowdsourced Sandbox Setting has Over 90 Community Members. I like the idea but would prefer something along the lines of the Dungeon Collaboration above, that is one person comes up with the map and maybe the major religions and others then populate the thing. This would then provide multiple versions of the setting that are each consistent but not necessarily consistent with each other. Also making it Public Domain would allow anyone to plop their 1-page dungeon in the hex south of the big city.