Logitech Trackman Trackball Mouse: Stay comfortable while navigating features on your computer with this ergonomic trackball mouse, which reduces hand and wrist motion. Accommodate multiple users in your household, since the ambidextrous design allows right- and left-handed operation.
This one is not as good as the older ones with the ball on the side. I do not like the ball being in the front. It is a lot harder to use. I wish I could find one with the ball on the side that isn't wireless!