Winn L. Rosch Hardware Bible, Sixth Edition

Trackballs

Just like its namesake in the Rodentia, the computer mouse needs room to roam and ends up almost anywhere. A mouse does not stay put because moving around is in its nature—and that's how you use it.

The problem is that many folks do not have room for a roaming rodent. Their desks are just too cluttered or they are traveling with a laptop and neglected to carry a desk along with them into the coach-class cabin. More insidious issues also involve mice. Pushing a plastic rodent requires clumsy, wasteful, and tiring whole-arm movements. Mice are inefficient and exhausting.

The leading mouse alternative, the trackball, eliminates these problems. Essentially a mouse turned upside down, the trackball is much like it sounds—an often big ball ...