Mark Cohen, Yeah, Rick has a way of starting really interesting threads. They suck me in nearly every time. One of the really cool things about a forum like this is that I get to post what little knowledge I have but I don't have to list the things I don't know. And let me assure you, what I don't know would span volumes compared to the odd paragraph on what I do. The Puget Sound Guitar Workshop sounds good though, it would be fun to attend as a student. (Right after I find time for the Woodenboat School in Maine)
Tip for mastering difficult chords:
I don't mean practice the song for which you learned the chord, I mean practice the chord. Over and over and over. If it hurts your hand to make the chord, practice more often. If it doesn't sound right, practice. If it takes too long to make it, practice. And when you practice, think with your ears more than with your fingers. And learn to ignore pain. Thirty minutes of real concentrated practice will leave you drained. If it doesn't, you're just going through the motions.
Go through some related changes. See how many different chords you can reach without repositioning your hand. See if you can make other chords by moving a single finger or two. Look for ways to move between chords using a planted "pivot" finger that doesn't have to move. Make chords with the fewest possible number of fingers so you have fingers left over for the fun stuff.
Here is a gratuitous chord exercise for the ambitious beginner. (If I haven't blown the HTML) It moves up and down from G6 to G7 to Gmaj7 and back down again. The trick is this: only two fingers may be lifted from the fingerboard for any single change! Under no circumstances may you reposition your hand. I'm assuming you are using a flatpick and all strokes are down, 4/4 time, two beats per chord. They are four-string chords so the unplayed strings must be muted. Keep this pattern moving until it's smooth.