Researchers at Northwestern University and the Delft University of Technology have developed a Game Boy that uses solar power and the energy generated from mashing buttons to run forever.
As the device switches between power sources, it does experience short losses in power. To ensure an acceptable duration of gameplay between power failures, the researchers designed the system hardware and software from the ground up to be energy aware as well as very energy efficient. They also developed a new technique for storing the system state in non-volatile memory, minimizing overhead and allowing quick restoration when power returns. This eliminates the need to press "save" as seen in traditional platforms, as the player can now continue gameplay from the exact point of the device fully losing power--even if Mario is in mid-jump.
On a not-too-cloudy day, and for games that require at least moderate amounts of clicking, gameplay interruptions typically last less than one second for every 10 seconds of gameplay. The researchers find this to be a playable scenario for some games--including Chess, Solitaire and Tetris--but certainly not yet for all (action) games.
It clearly still has some kinks to work out since it has to pause every 10 seconds, but it's a clever idea to use the button mashing to power the device. It seems like the kind of thing that could be applied to keyboards or, say, the energy generated by teenage boys' wrists. If you could harness the energy being generated from all that vigorous motion you could probably power a small country.
Keep going for video of the Game Boy in action.