Similar to the magnetically levitating bed, this computer mouse uses “electromagnetic hovering technology to do its thing, and it still has a respectable 6,000-dpi accuracy.” Best of all, this gadget is priced at an affordable $75. More information.
The only thing I would worry about is what happens when your hand isn’t on the mouse. Does it stay still, or does it float around like an air hockey puck? I mean, in addition to floating around it’s also wireless, so what’s to stop it from floating its way right off your desk?