WoW has this, the guild finder menu I think it was called. The only downside is that lots of guilds with only 1 member would flood the list, meaning you'd have to wade through a lot of spam just to get to the ones actually worth looking at. So I'd say in order for this idea to work your FC must be at least level _2_ and have at least _10_ members in order to post, to keep the clutter to a minimum. Good idea otherwise.