The humble beginnings of videoconferencing, the mouse, hypertext, online collaboration, and just about everything else that matters in the computer world these days. (Okay, not quite, but still.)
This article from Wired is really interesting. Not only does it offer an inside look at the origins of these technologies we now take for granted (they were conceived of much earlier than you'd think), it also demonstrates what a few people with vision can achieve even when no one else "gets it" until much later.
Not to be missed: the photo of the first mouse, made out of a block of wood!