i use a kensington studio mouse with my 12" albook, and i would highly recommend it. it's performed stellarly for me. it has good optical tracking (not perfect, but what optical mouse is) and the touch sensitive scroll pad is very cool.
Watch out for the Kensington Pocketmouse Pro Wireless. It got a bad review from MacAddict read it here, but with the note that it's a rare exception to an otherwise great line of products. I have a Logitech wireless mouse (standard white one) on one of my machines that I bought without a mouse, and have found it to be pretty good. But for the best ergonomics, I have never found anyone else's mice to measure up to Apple's one-button. It's the only one I can comfortably keep my hand on without wrist stress upward to keep from setting it off.
Microsoft Optical Wheel Mouse. High quality, low price, excellent OS X support. I got this for my PC, but liked it so much that it gravitated to my Mac - the PC is stuck with an ultra cheap PS/2 mouse.
I use the Kensington Turbo and Expert Mouse Trackballs myself. Some say it's bulky, I personally love the feel of these big trackballs. I have three of them, one at work, one at my desk at home, and one I carry with my PB. I love'm and would easilly recommend them to anyone.
The Mouseworks software lets you customize everything about the trackball... it's the icing to an already perfect peripheral.
Don't be hesitant to buy MS hardware. They make crap software, but some of the most amazing hardware. I got their first optical mouse explorer when it first came out and it lasted my a long time until I think the cord or connecter broke (my fault). I then bought another one and I have been using it every since. I too had this on my PC and it has now moved to the mac. And, it is indispensable for my video editting. Got the wheel programed for scrubbing, the left side button for undo, and the right side button for render. Saved me having to buy a wheel or some other accesory. When I get another mouse, I will definatly buy Microsoft again...maybe they should get out of the software business and focus on hardware only....hmm...Microhard?
I have the Logitech wheel mouse optical. See link above. It works great. I like it because I can use the mouse easily with either the left or right hand. I have used this type of mouse for 5 years now and I can't imagine 'switching' to another mouse. I find it very strange to use the Apple Pro mouse. I need a wheel and another button!