This is actually kind of gross, so if you are easily queasy or are a member of PETA, you might not like this.

There is a fish farming company in Honduras that has become completely self sufficient in regards to its energy needs. Basically, after the fish are gutted and filleted, they take the remains (guts, heads, etc), grind it up, cook it up, and turn it into bio-diesel. They use this to power their entire operation (electricity, vehicles, etc). It's a little gross sounding, but at least they are doing something with the waste.

Although, I don't necessarily feel that bio-fuels are the end-all answer to our energy problems (due to the stresses it puts on the food industry, etc.), it is at least nice to see a company transforming their waste into a useable product.

This reminds me of the very end of the movie Back To The Future. When Doc Brown comes back from his initial visit to the future, he no longer has to fuel his flux capacitor with plutonium, but instead he uses standard bio-waste (banana peels, egg shells, and beer). Maybe this is the way we are headed.