My son asked me if I could build him a robot. So I did, but then he said he wanted a robot that can speak, walk on its own and also be remotely controlled. So a few years later... yep, this robot emerged :-)
The heart is an Atmel processor on a PCB. In the head is a small breadboard with a shift register for the lights. A servo motor controls the head and 2 DC motors control the movement. An arduino speakJet shield is used for the sound. In the head there is a IR distance meter to avoid obstacles. In the back there is an IR receiver for the remote control.
The robot can listen to commands from the remote (when its nose is turned off) or run on its own. The arms do get in the way though, so avoiding obstacles results in falling sometimes :-)