Ahem,
I actually have a radio mouse an' all. Not bad actually, I tend to stick to Logitech and Microsoft stuff myself, I find these two brands pretty reliable - I hate to say it, but you seem to get good stuff for your squids whilst supporting Mr Gates in the style he has become accustomed to. Logitech also, from experience, is usually pretty trouble free. On slower PCs I found optical mice would sometimes produce cursor movement opposite to the mouse movement, random jumps onscreen, and so on.... rollerball versions worked fine.
Dave