Last year I pointed to some machines that turn themselves off -- these are called "Ultimate Machines," and generally take the form of a box with a switch. You flip the switch, the box activates and flips the switch back, turning itself off. That's all the machine does -- return it its steady state. But today, Jason Kottke (via David Gallagher) brings us what might be the Ultimate Ultimate Machine -- stick around to see what happens around the one-minute mark:
More examples: This Machine Turns Itself Off.