During Google's I/O conference yesterday, in which they announced (among other things) a DIY-friendly developer kit pairing Android with the Arduino microcontroller, we'd heard mention of a labyrinth controlled by a Motorola Xoom tablet. "Pretty cool!" we thought. "Labyrinths are always fun." Then we saw a video today of the labyrinth in action. Um, why did nobody mention it's a giant version, using a bowling ball instead of a marble?