Trackballs, why have they been blackballed? Everyone I loan my spare, I have three new ones just in case they stop selling them, Logitech mouse man marble to they immediately buy one for themselves.
My friend has CTS and cannot use a regular mouse with one hand because of the strain, trackball fixed him right up. Not only are they friendlier on the wrist the require vastly less desk space, they are easier to control and for precision work nothing beats a trackball.
My Gaming (counterstrike: source, UT2004, UT3, half life, team fortress, day of defeat,etc) buddies all have crazy expensive uber dpi programmable gaming mice that have lasers, and my 20$ trackball whips 'em every time. Why? no wasted movement, my arm is completely stationary when mousing, my fingers can keep the ball fluid and moving in one direction without having to lift it up, move it ove,r set it down, and continue mousing, one quick flick of the finger and the ball goes spinning in the desired direction, all while my arm is relaxed and stationary.
They are in fact perfect in play situations too.
How about some trackball love?