Good thoughts. A lurking non-member friend of mine (hi, greg!) sent me an e-mail with these additions --

1) Sit in front of a mirror and go through the changes of the chords so you can see what they look like from the outside. He notes that we all are used to seeing our chord hands from the "inside- out" and seldom from watching what they look like from opposite. Standard folk music for guitar is likely to be in C, G, D, A, or E. If you can get the hand patterns of these, you are well ahead of the game.
2) Get the sheet music or tab/chords of songs you know and like from recordings, and then listen to them so you can develop the knack of hearing the rhythm of chord changes in songs (e.g. how to tell a IV from a V, minors, etc.).
3) There are now CDs (banjo ones particularly) that just play so that you can play along and learn the changes.
4) Certain chords are dead-giveaways -- e.g. the B7 mentioned earlier -- the chances of it being in anything other that E are slim.

I thought these were all pretty good. I would certainly echo the earlier remark about being very careful not to disrupt a singer, or anyone else doing a solo -- that is a good way to become really unpopular.

yours,

Peter T.