Build a better mousetrap, Ralph Waldo Emerson famously told us, and the world will beat a path to your door. On the other hand, computer-industry folks have been trying to build a better mouse for years–and the world has stayed away from 99 percent of them, including some fascinating works of unbridled mad genius. I’ve assembled a gallery of ill-fated mice (plus a few trackballs and mousepads), mostly drawn from the invaluable Google Patents. Some of these presumably turned into real products; others never got off the drawing board. Herewith, brief moments of delayed glory for all of them.