It's a "programmable disco ball," a "cat toy for humans," and a "personal laser light show," all rolled into one. That's how one Matt Leone describes his latest creation, aptly known as the Laser Ball. To realize his dream, Leone drilled a set of holes into a garden variety tennis ball, and inserted about 14 laser diodes, each with an attached strip of diffraction grating. Said diodes were then synced up with an Arduino-equipped Teensy microcontroller