Re: (Sorry for reposting this comment.)
Hmm, you might want to check the settings on that -- I know on LJ you can set it to either "only mods can add tags" or "users can add tags". That said, you could set up a post for "Tag requests" or set up a bunch of tags initially for popular fandoms and hope people fill them out?
That makes sense, re: moderation (it was just a thought).
NP :) I'm off to class now though, so I'll TTYL :)