[Mario Mauerer] and friends were commissioned to build this 2m persistence of vision display (translated) for a party (in a hight-voltage lab no less). Dubbed “Display from Hell”, it uses 100 blue SMD LEDs to generate the POV images. They’re connected to an ATMega64 via shift registers. Their target speed is 600rpm for a flicker free image, which means the propeller tips are moving at 140mph. The board can be updated wirelessly via IRDA and plans for adding SD storage are in place. You have to see and HEAR this thing in the video embedded below.