The Pololu Zumo robot is an Arduino-controllable tracked robot platform that is less than 10 cm × 10 cm—small enough to qualify for Mini Sumo.
Warning: Last items in stock!
It includes two micro metal gearmotors coupled to a pair of silicone tracks, a stainless steel bulldozer-style blade, an array of six infrared reflectance sensors for line following or edge detection, a buzzer for simple sounds and music, a 3-axis accelerometer, magnetometer, and gyro for detecting impacts and tracking orientation. Just add 4 AA batteries and an Arduino (or compatible controller) and you are ready to push! No soldering or assembly is required.
Motors are included, The arduino is NOT
More info on the Pololu Website: http://www.pololu.com/product/2510