The Randomizer is a RedPower circuit that randomly emits Redstone signals on any of its three output sides.
This circuit will randomly emit Redstone signals on any of the three output sides when supplied with a signal on its input. When a continuous signal is being supplied, it will keep randomly firing signals on all three sides. It may send output to one, two, or all three sides at once.
The Randomizer thus introduces to Redstone circuitry an integral element of computing: randomness (see this Wikipedia article for a list of applications of randomness).