I bought this one and it is pretty cool: http://adafruit.com/products/306 http://adafruit.com/products/306 A little bit more expensive though, because it has a

I bought this one and it is pretty cool: http://adafruit.com/products/306 http://adafruit.com/products/306 A little bit more expensive though, because it has a microcontroller every 6cm.