I am a mouse user who is none too enthused about the crackling noises and occasional pain coming from my wrist so I'm looking to get a trackball. From the things I've read so far, it seems like which trackball is the best is complete preference, but that the finger (as opposed to thumb) controlled trackballs put less strain on your hand/arm/wrist/whatever. Right now I'm thinking I'll go with a finger controlled ball and I'm looking at the MS Optical Explorer. People seem to like the Logitech Marble Mouse the best but I think I need a scroll wheel, even if it makes my thumb hurt, as the wheel on the MS trackball might. Anyway, I'd like to hear opinions and preferences if people have experiences with these things. Thanks...