Dino Magri, Pedro Ângelo, Ricardo Lobo and Tiago Serra took some cheapo rc cars, ripped out the original pcb and replaced them with arduino in order to drive them with GameCube steering wheel controllers. Next they made a rather large circuit to drive their cars around and voila, a new MicroMachines racing game was born! Of course they couldn't bend to see the cars so the track is viewed via a projector on the wall. The whole thing is amazing but i cant say the same for the driving skills. :). If you want the documentation and the code you can check here with only requirement you know portuguese. If you're interested in the teams works you can check these sites also, labcdmusaxdatelier.
Frantisek Durovsky with a lynxmotion A4WD1 v.2 rover as a base and an AL5C robotic arm builded a robot equipped with Xbee wireless control by remote PC, GPS module,main controler ATmega128 and Visual Basic 2008 as control program. The construction is pro-like and so is the operation, you can see in the video the smooth and fine movements.
Luis Cruz from Honduras builded a video game system using 4 microcontrollers. One for the wireless controller (an atmega168), one for video, one for monophonic sound, and the last one that receives the information remotely from the IR LED in the controller. Yes, he also builded an IR contro...
Cerealkiffer demonstartes a 18v remote for fireworks detonation. It has a scalable range of approximately 50m and the total cost according to builder is around 5$.
If you can read German more info can be found here.
Justin McAllister made an inverted pendulum balancing robot with just the bare essentials but not sacrificing functionality or fun, plus it looks like the small brother of segway. :) More info and video here.
Peter Jakab builded with PIC a remote control for up to 8 devices. It can work as a radio or infrared remote control, depending on the components. Each device output can be configured to be momentary (turned on while you press the button) or latched. Latched outputs can be toggled on/off by one button per channel, or turned on and off by two buttons per channel.