I bought some two-pin tiny motors from Radio shack. I want to write a program that allows the output power (voltage level) to a pin be set in a program. Can Arduino do this? Can someone give me the precise terminology for what that kinda thing is called so that I may look it up in the reference docs? thanks!
Oh, maybe it's analogWrite() - Arduino Reference
want to write a program that allows the output power (voltage level)
Power and Voltage are different (but related.) So you are asking for programmable voltage. The PWM pins controlled by AnalogWrite produce a square wave with a programmable duty cycle.
For the case of a (relatively) slow-moving mass like a motor, this is effectively the same as a variable DC voltage. (The average of the signal is similar to a constant DC voltage.)