Oooh! A yellow badge convention...
Anyway, might be worth checking out
http://Ning.com, which is being used in education a fair bit these days.
Not a forum - although there is a basic forum in there - but more a site for setting up custom social networks, which amongst other things gives users their own pages where they can upload articles etc via blogs, and so on. Also the usual stuff like comments can be made on most things by other users, activities can be scheduled, chatrooms, separate groups can be set up within the network, etc...
It's free to begin and up to a certain bandwith/storage capacity (don't remember what size, but 10GB rings a bell), completely drag'n'drop, so it's a doddle to use and you've probabyl got nothing to lose by checking it out. Took me about 5 minutes to throw together
this delightful little site