A team at Case Western Reserve University led by Michelle Rasmussen and Daniel Scherson has tapped into the metabolic system of a cockroach to produce electricity. This isn't the first time anyone has tried building a cyborg bug of sorts. A University of Michigan team tried it using piezoelectric materials. What's interesting here is that Rasmussen's group used the insect's own body chemistry to produce electricity.
The article also says shiitake mushrooms contain the same sugar as cockroaches and have also been used to produce electricity. Hopefully mushrooms and roaches alike will be able to exit the Matrix at some point.