He programmed the screen and coin acceptor using an Arduino microcontroller, used a laser-cutter from school to make the front interface, and made a locking mechanism to prevent thieves from pulling it out of his locker. The device can dispense two types of soda—and the occasional special treat. He used his new machine to ask his girlfriend to prom, having her invitation drop out of the vending slot on a Dr. Pepper can.
Check out his Instructables page for the project, if only for the really adorable comment from his dad.
[h/t Laughing Squid]