Has anyone tried building a speed control for a small radio control dc motor?

I have a Futaba radio which I am going to use for this project.
Any ideas where I cam start?

The 16F648A has a PWM on the B Channel.. this you can use for a motor control speed extremely easily... a N Type Mosfet and the pwm will allow you to do close to the entire range of the motor. (depending on the motor voltage).

Dwayne