Principia Infecta is full of worldbuilding ideas, all presented in a rather unusual way.
When he emailed me the link, Reason (the author) described it as “an idea well for GMs and other folks,” while the blog’s tagline is “A slow river of world-building by glimpse and omission.” The bottom line? It’s tough to pin down, and you should go see for yourself.
Reminds me of a community I tried (and failed) to start on LiveJournal which was basically just a place for people to post little bits of stuff. Pieces of technology, events, stuff like that which would flesh out or add to a setting/story but were not nearly enough on their own.
Was it a complete flop, or is there some good stuff there that you could link up?