Cheap 5v power supply for breadboard

Some guy in my digital circuits lab said there's something called a voltage actuator that you can buy at Radio Shack, which will take a 9v battery and give you 5v power for a breadboard. The guy at Radio Shack didn't know what I was talking about. Does anyone know what I'm looking for?

>>8
Urrr?  A voltage regulator produces fairly clean DC output, right?  Are you trying to clean up more ripple?