I did the Berklee Guitar Sessions a while back (the year 2000). It's a week-long camp-type thing where you go to Berklee, live in their dorms, take classes, have hosted jam sessions, see performances (my session included Vinnie Moore) etc. and run around on your own during the off-hours. It was pretty fun and affordable way to really immerse yourself in guitar for a short time, surrounded by other players who are serious about guitar too. My roommate was a bluegrass player from somewhere in the south who was AWESOME and he picked up some of the stuff we learned much faster than I did. I also roomed with a cool, chill blues type guy. There were plenty of rockers around as well.
Since I'm a drummer, I'm somewhat curious about Drummer's Collective in, I think NJ. I don't know any of the details - how it's run, how long it lasts, etc. I think Jason Rullo is an alumnus.