LeoneLabs on Instructables posted this fantastic how-to on adding 14 lasers to a regular tennis ball to make a Laser Ball. Why? He says that it’s fun to build, it can be done in an afternoon, and “lasers are cool.” The lasers are driven by a Teensy USB Development Board, which is stuffed inside the ball and controlled from outside with an infrared remote control. The Instructable shows you how to make your own in painstaking detail, but you can also follow the build step-by-step in this fun video. [Thanks, Luis!]