See, here's the deal. I've wanted a 3 button scrolling mouse for my Mac for 2 years. I bought a Kensington Studio Mouse about a year and a half ago, but it really sucked. It's little scroll area didn't work well for me and it just didn't look as cool as the rest of my Mac. In fact, the last part is the problem. None of the other mice that have been out looked as cool as my Mac. So, I stuck with the Apple Pro Mouse that came with my iMac.
But, seeing the Mighty Mouse made me realize I had to have one. It's just so cool. It's sleek. It's white. It matches my Mac. Plus, it gives me buttons.
After I got the mouse, it took no time to install. I unplugged the Pro from my keyboard and stuck in the Mighty. Boom. Working. Then I installed the Mighty Mouse software so I could program the buttons. This required a restart, but it's forgivable. Mouse drivers are a bit low level and you can't just restart the window manager (Aqua) on the Mac.
Once the Mighty Mouse software was installed, things got even better. By default the two top buttons are the primary click (as if you didn't have a left and a right), the middle is Dashboard, and the sides are Expose. I reprogrammed the top buttons to be left and right and left the others as is to see if I liked them. Two hours later, and I think I'm going to keep the middle and sides programmed to Dashboard and Expose.
I have to say, I've really been missing out by having a single button mouse on the Mac. Just having the ability to scroll makes it feel like you can do things faster. The cool thing is that I can scroll vertically AND horizontally. Love it.
Bottom line: This mouse ROARS!*
* Obscure reference to The Mouse That Roared. I played Professor Kokintz in the play in 7th grade. I've never seen the film, but it seems like a must-see Peter Sellers performance.