My brother in law bought my sister a Kensington Studio wireless mouse, it arrived today so I stopped over & set it up for her.
I should tell you that I had the original Studio Mouse (wired) and didn't like it, I thought it felt cheap and the click sounded tinny, I wound up returning it.
It seems that Kensington has improved the quality of the Studio Mouse, this one seemed made much better and the click was much better feeling and sounding, the base and mouse look great with the iMac.
The one thing is that it has a very flat surface which I'm not used to, my Logitech MX700 is more ergonomic.
Fair warning, if you're using OS X 10.2 DO NOT install the MouseWorks software from the disk, download the software.
I learned the hard way I installed from the disk and the iMac crashed on me (On the disk cover it says to first check if there are updates but I was in a rush so I didn't look.)
Once I uninstalled the software and installed the updated software everything was fine.