I wondered if I could get a 30cm x 30cm wooden plate to juggle a ping pong ball. It uses 4 high speed RC-servos for the ball-hitting and 12 photo-transistor-LED pairs to get the position of the ping pong ball. The sensors are configured in a way that the timing for the upward motion is just about right. The controlling is handled by an mbed prototype board (mbed LPC11U24).