Well, from some of the replies, I'm baffled because if you go to Adafruit you can get a continuos rotation servo. It has a speed of up to 60 rpm. http://www.adafruit.com/index.phpmain_page=product_info&cPath=34&products_id=154&zenid=c024fcf1859f93413f102e4fdb311816
I hooked one up with the servo program which involves a potentiometer. I think I changed the map to 0 to 360 instead of the 1 to 179. Not sure but I know I got it to work. Anyway when you turn the pot one way it goes forward (cont) and the other way reverse (cont). Works just like a slow rpm motor.