Programming Tips - How can I use an Arduino to control a 9V motor?

Date: 2009sep14 Product: Arduino Q. How can I use an Arduino to control a 9V motor? A. There is a diagram on page 71 of the the "Getting Started" book but no schematic so I made one:
Arduino IRF510 MOSFET Digital Output --------------------------------------------- G (eg #7) +9V -----------+------ Motor ------+------------------------ D | | +------ |< ---------+ Diode GND -------------------------------------------------------- S
I was not able to figure out how to control a device that had a high voltage. ie one not supplied by the Arduino. If you know, maybe you can leave a comment.