Thanks very much, A13W!
To organize a game, generally most people here either use the AI War Meeting Grounds, the IRC channel (linked from there), XFire, Steam invites/the Steam group, or so forth. I think the IRC channel has been the big winner so far, but that may change now that we're out on Steam. There are other forums where people organize AI War games from time to time, such as Gaming Trend and Relic News, but the majority of people are here or in IRC, from what I can tell.