AKE an ordinary, albeit old, Coke Machine. Add an LED display and clock display in the window. Modify or rebuild the machine's guts so you have complete control over what happens when buttons are pushed or coins are deposited, and when sodas and change is dispensed. Thus, people can buy Cokes "on account" by entering a password with the buttons, or perhaps check their email. Then, write a general-purpose API so that anyone can write games and other programs to run on the Coke Machine, using the Coke buttons as input.
hat was the idea behind the Coke project, which is what I was working on throughout my senior year, and especially during the summer before leaving for grad school. It was quite an extensive project, involving everything from high-level unix software, down through assembly language firmware and digital electronics, to analog and mechanical circuitry. My part, which was hardware and firmware, was pretty much done when I left... However, the people in charge of writing the software never got around to doing it, so the whole thing (I believe) currently does nothing.
or complete details on this project (including the most extensive documentation I've ever written for anything), you can check out the Coke Machine Docs