I bought this in a job-lot store for a fraction of its original price. The Stir Chef. It's incredibly cool - so cool that I can't believe they were in a markdown shop - and so simple that it's hard to believe no one ever came up with it before.
Basically, it's a high-torque, low-speed motor with three extendable, spring-loaded legs which clip to the edge of a pot. An extendable shaft passes through the center of the unit and is rotated by the motor. On the end of the shaft, you clip a paddle corresponding to the diameter of the pot you are using.
Set whatever you're cooking to simmer, turn on the Stir Chef, and you can go about your other business in the kitchen - the Stir Chef does the stirring for you. It works great for pudding, sauces, soups, and even high-density, hard-to-stir crap like oatmeal, corn meal mush, and grits. In the picture on the left, I have it stirring a 6-cup batch of scrapple (a mixture of pork, spices, and cornmeal) on low heat. Scrapple gets so thick as it cooks that it hurts to stir, but the Stir Chef handles it without even heating up.
Anyway, I don't want this to turn into an advertisement, so I'll cut it short. If you find this thing at a remainder shop near you, buy it, you won't be sorry. Hell, it even comes with batteries so you can play with it in the car on the way home.