I signed up to "GM" a few games at KublaCon this year. Kubla is a 4 day game-a-thon held at the Hyatt near SFO. Here are the times they gave me:
Mage Knight Board Game: The Lost Legion, Friday 3pm-8pm, 4 players
Through the Ages: a Story of Civilization, Sunday 4pm-9pm, 4 players
Apparently GMs aren't supposed to play unless they are short on players. Well phooey on that I say. Anyway if I get enough people to sign up to make these official events, I get a free pass, woohoo!
I guess you can't actually sign up for tabletop games until the event starts but you can see the schedule here: http://kublacon.info/
Last year I was there but was a little underwhelmed by the ratio of tabletop board games to RPGs and miniatures games. It was a little difficult to find an open game to play by just randomly walking around. So this year I plan to be a little more actively recruiting for games in advance.
So far I have only posted the two games, and I know Saturday there is some 18xx going on which I plan to partake in at least for a while. Also I think it'd be nice to bust out some other longer games that we never get a chance to play, if anyone has suggestions I can create an event.