"Microbe-powered 'fart' machine stores energy". No, seriously:

...[G]iving small jolts of electricity to single-celled microorganisms known as archea prompts them to remove C02 from the air and turn it into methane, released as tiny "farts." The methane, in turn, can be used to power fuel cells or to store the electrical energy chemically until its needed.

"We found that we can directly convert electrical current into methane using a very specific microorganism," said Bruce Logan, a professor at Pennsylvania State University, who details his discovery in the journal Environmental Science and Technology.

We envision this as a way to store electrical energy, to convert electricity into a biofuel," he said.

(Via Rand Simberg.)