[rconti]

The original hockey puck mouse had a ball (I had to Google it to confirm my memory, since otherwise it's just your memory against mine!)

https://en.wikipedia.org/wiki/Hockey_puck_mouse

I remember the later G3 education models my school had having a "laser" (I assume LED?) mouse.

Likely the iMac went the same way.

[karmelapple]

I remember the hockey puck mouse had a ball because it was a pretty fantastic ball: it was dual toned, one hemisphere white, the other Bondi blue. As you rolled the mouse, you'd see the ball turn and have a neat color display through the translucent plastic of the hockey puck mouse.

That was my favorite part of the hockey puck mouse - it was one of those little moments of "surprise and delight" from Apple. And alas, I can't find a good video of it online.

[zumu]

Ok, so my memory is a little foggy. Looks like the laser one didn't come out until 2000, but the hockey puck was USB at least!