Willy Wonka could have powered his Great Glass Elevator on hydrogen produced from his chocolate factory.
Microbiologist Lynne Mackaskie and her colleagues at the University of Birmingham in the UK have powered a fuel cell by feeding sugar-loving bacteria chocolate-factory waste. "We wanted to see if we tipped chocolate into one end, could we get electricity out at the other?" she says

Just one more thing to love chocolate for, right? I knew I should have kept my initial science major instead of my english one. I too could experiment with chocolate for a living!

Seriously though, found this very interesting.

~Heathyr

[ It's interesting more for the broad implications than the actual experiment. I'm sure recycling 100% of chocolate waste couldn't generate enough electricity to make a meaningful contribution to our power needs. But, if you can make a general purpose bacterium (or set of bacteria) that can produce useful byproducts while eating, say, normal garbage, then we've got something. -k]

New Scientist Tech - Technology - Chocolate generates electrical power