The BoE-Bot Robot Kit (USB) is a complete mobile robotics kit.
The 3pi is a speedy line follower, but sometimes you just want to add your own hardware to the mix. Here's the expansion board just for you!
If you're looking for a base for your next robot, look no further than the Rover 5. This 4 motor monstrosity takes any terrain by storm.... just don't take it out in a storm... please!