Instead of the boring words-per-minute (wpm) rating when talking about typing speed, how about going by revolutions per minute (rpm)? Seen here is the USB Mice Wheel (that's the product name, though there's only one mouse there), which responds to your typing speed. The faster you go, the faster it turns.
The product requires you to install some software, and it works only for Windows XP. If you'd rather not plug it in, you can put in some batteries and it'll still work, except the speed will be controlled by a knob and not your keyboard. … Read more