DC motors instead of modified servos this time.
Nice Hoff!
Where are you buying the parts like the chassis, motors, etc.? I'm looking for an inexpensive way to get started with an Arduino robot.
Jake
Chassis? What chassis? We don't need no stinkin chassis!
Couple places with some 'cost effective' chassis, motors, and motor controllers:
Spend some time researching motor specs and motor controllers. Spend even more time researching if you think you want to build your own dual h-bridge motor control circuit. You need to make sure your motor controller is capable of handling the power requirements of the motors you buy. The smaller rovers generally have fairly low power demands, but not always (the tamiya dual motor gearbox in particular has some oddball motors, with low voltage requirements paired with high current requirements).
You can see one chassis pretty well in this vid:
It's a dollar store erector set knockoff bulldozer kit with 2 servos modified for continuous rotation. That seems to be the easiest route to turning wheels/tracks etc.
The vid in the first post is a Tamiya dual gearbox and Tamiya track set that I rigged up with another cheap-o erector set.
Here's a couple of bad pics:
The second is a board with an L298 driver which seems to work well with the Tamiya box. It may not be the best choice but it was fun to build 
The gearbox is a little model that you assemble and the track set is just a bunch of parts. I got them both from Sparkfun.
Yea, bots and stuff that rolls around under power are cool to mess with 8)
That board turned out to be pretty large and I think I'm going to try to duplicate it only smaller. Maybe with a home brew PCB 
Here's a link to a thread about my L298 adventures:
Thanks for the info Hoff and Jraskel. I'll check it out.