On December 9, 1968, a group of engineers led by Douglas Engelbart crowded into an auditorium in San Francisco to show off a groundbreaking new system they'd designed for interacting with a computer. Moving beyond the cold realities of the keyboard (and even the punch card), Engelbart's creation would open up a new world of computing from that day on. His invention: The mouse.

40 years ago tomorrow, Engelbart demonstrated the mouse along with numerous other innovations in front of 1,000 computer professionals, marking its official public unveiling. The research took six years and the work of some 20 engineers just to get to that point.

The first mouse was quite primitive by today's standards. It didn't even have a ball inside (much less an optical sensor), but rather two large discs set perpendicular to each other inside: Movement of one wheel handled location along the x axis and the other dealt with the y axis. The original mouse was quite large, barely fitting in the user's hand, but Engelbart envisioned that you would keep one hand on the mouse at all times and the other on a special one-handed keyboard instead of a standard QWERTY-styled model.

It would take years for the mouse to catch on (beginning primarily with the introduction of the original Macintosh in 1984): By that point Englebart's patent had expired and he never received any royalties for inventing the thing. Try to imagine how much money he'd have if he had earned a penny from every mouse ever produced...

In lieu of compensation, our gratitude and salutations will have to suffice. If you want to take a real stroll down high-tech's memory lane, check out the complete 100-minute demo from 1968 -- along with Engelbert's other pioneering innovations like hypertext and screen-sharing technology -- at Stanford's video archive site.