Since my Macbook only has two USB ports, I'd like to get myself a mouse that can pair with the Mac's built-in bluetooth. The obvious choice is the Apple Magic Mouse, but at $70 it's pretty much overkill. I don't need the touch functionality, since the Mac's trackpad already does a great job with that.
I'm mostly looking for something that allows me accurate control, isn't too large (so I can toss it in my backpack), and isn't too expensive. And looks nice next to the Aluminum Macbook, or course. :)