It's official - the computer mouse is 40 years old today. Good grief I feel old, I'm older than the earliest mouse. That's somewhat sobering.
The first mouse was made of wood. It was much, much larger than the hand-held devices we have today and it was much less precise - but it was essentially the same device, a wheel mouse, and they even had HTML hyperlinks over which it could hover.
We all feel very advanced now because we have mice, we have PCs, we have iPods. Presumably in the sixties they felt superior precisely because they didn't have those things. The mouse, though, was the first step in making computers easy for non-computing types, one could argue, although it didn't fully hit the mainstream until Windows 3.0 came out in the nineties (I know it had been on a number of systems for a while but nothing as popular). It's a milestone worth marking.
You'll note that in the film of the first demonstration, which you can find here, the inventor apologises for calling it something dumb like 'mouse'. You can't help but wonder what he'd think of modern terminology. "Megaflop" is a personal favourite that I apply to my career when I'm feeling depressed!