Remember the days of your computer mouse getting a little squirrely and the remedy being to partially disassemble the mouse and do away with all of the lint, dirt, and general desk gunk that had found its way onto the roller ball and its sensors?  (Which were also the days where a mousepad was mandatory.  And the roller ball made a pretty great toy too.) Thanks to Microsoft, that is fortunately a distant memory as on April 14, 1999 their first optical computer mouse was introduced at a tech convention in Las Vegas and eventually revolutionized our mousing habits.