www.4qd.co.uk will astound you with the amount of information they provide on motor control. As an aside they also have a suitable controller for your application. Using a 5 volt drive from your arduino it'll give you all you need plus regen braking. I've no commercial interest in the company, just a very happy customer.
Thanks for the info! :) Sorry, what is a "5 volt drive"?
But the prices seem high. The "Pro 150" is 140 pound = $225 I can't afford it :~
[quote author=Coding Badly link=topic=106315.msg797843#msg797843 date=1337329723]
That website looks good, thanks!
If I buy a used scooter could I use the motor controller that's inside it with an arduino?