I'm surprised there's little information about the "scrollpoint pro" mouse. It's one of the coolest things ever.
Here's some juicy shots:
First of all, it supports 360 scrolling, it's like a little tilty stick; SIMILAR to the trackpoint, but more deep... and it's for scrolling, not moving the cursor. It's pressure sensitive and can be controlled to suit your needs. Windows 7 automatically detects it without drivers; and I find it to be fine without any customization.
Next, the button on the side (near the thumb) can be set to a variety of functions; I like to set it as ctrl+z, so it can automatically undo actions: I'm that lazy.
Finally, the scollpoint stick GLOWS! I haven't seen such a stylish IBM product before (and probably never will again). I also enjoy the curvature, I haven't had a mouse that fit my hand so well.
What's amazing about these, is that they were released in 2002. And Apple just released their "magic" mouse which supports 360 scolling... ahh... 7 years too late.
So, I bet you're saying "WHERE CAN I GET ONE?!?!" Well, IBM, rather lenovo, has discontinued them. It's a pity, because, they're much better than the regular scrollpoint.
I was able to buy one right before crapovo discontinued them. Sadly, mine had a lenovo logo (which, I wouldn't have bought if I knew); but a little sandpaper solved that.
These things are quite durable, I spilled a bunch of juice in mine, and it still works. Had it for 2 years now, use it every day.
It's very hard to find them; getting one with an IBM-logo is quite in vain. Oh well, good things always come to pass first.