Looking at the profile titles this morning I had an idea, though I'm not sure how it would be implemented. I do think it might encourage people to join groups and to possibly pick one as their main home here at GG.
What about a drop down bar with the names of each Clan/Group and under our name, instead of "Senior Post Whore", it showed which clan we were in? You could even have it linked to the URL for that clan's forum here at GG. It might do well since some of our titles are a bit outdated. ("I'm Rick James, Biatch!")
Default would be "Free Agent". You could even have a modified "Free Agent" that people could use to show they were interested in joining a clan/group.
Geezers in Arms
Laid Back Geezers
The Co-Op Syndicate
Windy City Geezers
Free Agent (in case they decided to leave a group)
Just a thought... not sure if it is even possible.