Sure, you'll need a foot pedal for the mouse clicking, which presents a problem for those disabled users who might have hoped to use such a device. But wait, there's a version that solves that problem, too. Check out the video to see this contraption in action.
SmartNav is available in three versions, the AT (assistive technology) version which lets you click on an item by dwelling over it, and its software also includes a virtual keyboard. As you can see on the video, this looks like it might be quite tedious for typing. The EG version has a foot switch, and is aimed at wrist strain sufferers, while the standard version is for those who want to increase their productivity and speed. Now if they can just bring the price down from $298.95.