I don't think an incentives system for game activity is a good idea. For most online games, more in-game activity helps gain in-game utility. A gaming clan is intended to help its members all gain in-game utility, and incentives for game inactivity would be counterproductive towards those ends. Furthermore, forming a SGG or LWGG would probably draw many of us towards whatever game it is implemented in while likely only resulting in a slight decrease in activity for those already there (maybe an increase for those games where managing a clan takes a lot of work).

However, the idea of forming gaming clans as a way to get publicity for LW or SIAI could be a good one in games with a large social aspect. Still, I would not recommend incentives for inactivity, because increased interaction with other players would increase the effectiveness of a gaming publicity drive. Also, I think a Less Wrong clan would be much more effective than a Singularitarian clan, because most people would probably at first write of "Singularitarian" as some nutcase cult belief, and have no interest, but there are many people who desire to become less wrong and could be helped out a lot by this site, and many of them would learn about SIAI from LW after we hook them in.

Another possibility to use gaming productively is to try to start up a LW- or SIAI-backed MMO and use it to generate revenue. It seems unlikely that this would be practical, but I'm not sure of that, so I figure throwing that idea out there can't hurt.