Coincidentally, I'm currently working on a browser based game (I know I've been doing several games lately, but this one is remotely hosted and can stay up 24/7) that should be ready for beta testers fairly soon. Once it's ready I'll post a link here. In terms of making it a group project, I'm not sure how I could release the source code without making it rediculously easy to hack the game, but if people submit PHP code snippets or suggest features I can try to integrate them into the game.
it more likely for all of us to commit group suicide than have a site wide project that stays together for more than 10 minutes before someone disagrees with someone and the project is canceled and we waist a whole bunch of time on some unrealized dream of yours.(Pi's dream, not gold's.)