I'm almost always up for getting together to wrench on someone's car...as long as I don't have to drive too far. Since I'm near Washington DC, that pretty much means I'm limited myself to things around the DC area.
But there's nothing that I wouldn't want to try to do on a 911. While I don't have a ton of experience, I usually consult forums like this, as well as other local enthusiasts, and then dive in. I dropped the motor from my '72 about 2 years ago. And I recently replaced shocks on both my cars. I helped a buddy drop the motor from his '79 930 last spring. I also just finished installing GHL headers and muffler on my 930...as well as replacing the front rotors and brake pads. And now I'm diverting my attention back to the '72 (have new SS brake lines to install, and then another motor drop prior to rust removal and RS flare installation...all after a DE in December). Unfortunately, I don't do a good job of documenting the installs/mods.
Group drives are cool too, but I'd probably drive my 930 for that since its a my daily driver. The coolest part of group drives, IMO, is the chance to see what everyone else is doing with/to their cars. For instance, my '72 is meant for track work. So I could share my experiences with roll cage install, carrera oil cooler install, Sparco seat install, etc. While we can talk about mods here, its much more effective to see what someone did first-hand.