I've been experimenting with several different coding styles for plug- ins. Lately I've been curious about the difference in performance between using local variables vs. instance variables for storing state. JSLitmus, while not itself jQuery-based, has just given me the answers I've been looking for. I found them a bit surprising:
http://www.fatdog.com/litmus_tests/InstanceVsLocalTest.html (Apologies for the color scheme! :-) Howard