Well Apple's done it again with the so-called "Mighty" mouse. Their 3 or 4-button wonder is great, as long as you don't get hooked on using the little scrollball. Never mind the fact that you can't move in X and Y directions at the same time (as you can using 2-finger trackpad scrolling)-- the trackball is a piece of junk. I mean, the build quality is nice (just like those Apple III's had heavy-duty aluminum chassis), but after about a month of frequent use, the thing gets jammed with gunk, making it largely unusable. And yes, I wash my hands regularly...
I have found the little nipple/scrollball on the mighty mouse too-wiggly for my taste. I guess with my next iMac (24'' baby!) I'll have to get another Logitech to replace the Mighty mouse it will come with.
Currently I'm in love with the features of Logitech MX Revolution Cordless Laser Mouse
I'm hoping that a wired version of the MX Revolution will be available soon.