I had a love /hate relationship with the Mighty Mouse. I loved how it was color coded to my iMac G5 loved the idea of the multi-direction scroll ball.

However, the problems outweighed the reality of the device: the four touch-sensitive buttons were flakey, especially the ones on the side. In the end, I shut them off completely. The right click was ok, but sometimes it just would not register the correct click.

Now, with everyone else's main complaint: the scroll ball. As I said, the idea of it was great, but it quickly crapped out after collecting desk gunk, skin and lint. Fixing it wasn't really an option either...so for the money, it was a failure in my mind.