Thank you for your answer lefty!
I'm trying to build a little tank (as a first project), I'm buying the beginners kit for the arduino board as well as this:
http://www.watterott.com/en/Dual-Motor-GearBox
http://www.watterott.com/en/Adafruit-Motor-Shield
How do I know if those 2 DC motor's (3-6V) will get enough power from the arduino Duemilanove board?
Thanks in advance!