I had this really fine post ready to post and my ATT dsl disconnected and I lost it so I will just say (cause I don't want to write it all over again) that besides my original group Yahoo! Jams and Mailart, which will always be my favorite group, I have found some other groups to join. Nervousness (which has changed vastly since I first tried it out years ago) and Monday Art Day, have already provided me with some great trades and some new group swaps.
Also, some of my old friends from ATCards have joined forces to start a new group called ATCsforALL. I love love love this new group and hope to have lots of fun there.