I've been using a Microsoft Wireless Intellimouse for about a month now. It's a bit bigger and heavier than the Optical Intellimouse I had before (mostly due to the two AA batteries, I'm sure) but it fits very comfortably into the hand and feels natural to use. In my case there's a digital telephone and a Dilbert calendar between the mouse and its receiving unit, but it still works just fine. If you want a new mouse this is a good choice IMO. I don't know what happens if you work close to someone else who also has one, though.