My very first encounter with electronics - a very simple manually controlled robot. The main brain controlling it is a Attiny2313 + a motor driver board based on TIP122 transistors. At the time when I built this, I had no idea about a chip called L293D!
It uses two DC geared motors, uses a differential drive (to keep it simple, I made a trackbelt using rubberbands :D).
Accepts signals from any RC5 based Infrared remote (like a TV remote). On board Attiny is responsible for the RC5 decoding.