The first computer mouse
Way back before Laser and Optical mice in 1964 there was a wooden contraption built by Douglas Engelbart the inventor of the computer mouse. It consisted of two gear-wheels positioned perpendicular to each other -- allowing movement on one axis. However the first computer mouse intended for navigation on a personal computer shipped with the Xerox 8010 Star Information System in 1981.
(More images after the jump)
Be careful: there are millions of iFanboys out there who insist that Apple invented the mouse.
Just head over to iWikipedia and see how hard they fight to protect that "fact".