We've never understood trackballs. Like the folks over at Dvice, we too remember being told that everyone would be be using them in a few years. That was 1995.
We tried our hand(s) at it too, with one about the size of a softball that was attached to an even bigger mouse--both of which were supposed to eliminate RSI forever. Years of physical therapy later, we're back to our old wireless Kensington. But we digress; clearly there are those still loyal to the trackball, for Genius has invented one that can even be used on the road by clipping it onto the laptop itself.
Then again, the maker of the "Traveler 350" never seems to let logic stand in the way of a product idea. Genius is the same company that came up with a . You do the math.