When I first tried it, I really liked the Mighty Mouse, so when I got my Mac, I ordered the bluetooth model. After using it for a few weeks though, I'm finding I don't like it for Photoshop work...or anything else, for that matter.
So I went back to what I really like using - the Microsoft wireless mouse 6000, as part of the "Microsoft wireless desktop for Mac" set. Yep, that means I also switched out my thin aluminum keyboard too....much as I thought I liked it, the keys were too close together for me to type accurately without many errors.
-Bryan