Old thread I know, but have to comment.... trackball mice, IMHO, are the best way to go for gaming. Control is excellent, response time to turn rate is faster than you would get with a regular mouse. What makes it even better is that for multiboxers two of these babies can be side by side and take up very little room!

Both my Logitech trackball mice (the ones pictured in the first thread) sit on a mouse pad, that's how much room they take up!