The Dagu Mr. Basic Mobile Robotic Platform is a simple 4WD robot chassis with an aluminium base, 2 motors/gearboxes and a 3xAA battery holder. The prototype PCB on top is double sided with plate through holes. The motors are rated 4.5V-6V with a no load current of 250mA and a stall current of 1.8A @ 4.5V each. Sold as a kit.
Mr Basic from Dagu is an excellent small robot platform. It is designed to work with the Dagu Mr Basic Motor Controller or use your own to drive the 4WD chassis.
Note: Mr Basic is sold as a kit and requires assembly
Some great examples of Mr Basic can be found at the LetsMakeRobots site where a competition was held to see what could be done.
Here is one entry fighting fires...