Don: Nothing.

Y: Nothing!?! Are you on a diet or something?

D: Not by choice. To be honest, I'm trying to save money by buying less food.

Y: Why?

D: Because I'm spending all my money on putting gas in my car and heating my home. The other day I filled up my tank and spent over fifty bucks! And you don't even want to know how high my heating bills have been.

Y: I hear you. We're all in the same boat. But check this out: scientists at Arizona State University are working on a fuel cell that uses bacteria to produce energy from waste material like sewage or pig manure.

D: You mean they can generate energy from garbage? Sounds like science fiction.

Y: I know, but this is for real. It's kinda technical, but the basic idea is that bacteria are good at breaking down almost any kind of organic waste. They eat stuff like sewage and manure, essentially. And when they do, the waste material releases electrons. The so-called "microbial fuel cell" uses the freed electrons to generate electricity.

D: That sounds great. So where can I get one?

Y: Nowhere, yet. Microbial fuel cells are still in the early prototype stage. But one day they could make a huge difference. The researchers think that in time, the cells could produce around twenty-five percent of the world's energy demand and help reduce our use of fossil fuels.

D: But meanwhile, I'm starving.

Y: Wanna share my lunch?

D: That depends . . . what do you have?