I mean, this is for the global community rather than a gaming group's local community, and the gaming group who're doing the work aren't a single group, either, but a huge mess of different geeks and gamers from around the world, but it is definitely the best thing I've seen. It's fantastic.
At uni, WARPSoc ('Wargames and RolePlay Society') did a few fundraising type things - 'LarpAid' was a charity LARP event including a tournament and a few stalls. I don't think we raised very much, but it ran for at least a couple of years. We also did a geeky Calendar Girls style calendar, which again was fun but didn't raise much (but does mean there's a photo of me in my underwear with elf ears and tied to a tree).
I guess the best thing we ever did for the local community related to the fact the woods we larped in were at least rumoured to also be home to magic mushrooms. So there we'd be, dressed as orcs and elves and (in the summer at least) as often as not in our bras and covered in body paint, casting magic spells, slaying vampires and screaming from the sacrifical altar. As non-gaming types wandered the woods seeking a different type of escape from reality. Depending on your stance, this was either beneficial in dissuading people hunting the shrooms, or beneficial in adding to the magical experience of it all.