One man's poop, another man's fertilizer and fuel. It could actually be the same man if he owned an anaerobic digester.

In the absence of oxygen inside a digester, bacteria break down the compounds in sewage to create gaseous methane, which can be used to power gas stoves or converted to electricity. And the leftover solids are great fertilizer--high in nutrients like nitrogen and phosphorous, safer than raw sewage, and stench-free.