Wow. This is what Cambridge, MA is doing:
They have also installed a work by conceptual artist Matthew Mazzotta: a streetlight powered entirely by dog droppings, called the ParkSpark Project.
It works simply: You put the dog poop into the large container, where it is digested by bacteria, creating methane gas, which can then be used to light a lamp. Biogas digesters like this are often used on landfills or for large amounts of cow manure, but it's unusual to see it on such a small, human scale.
I greatly look forward to the day when Boardman coal plant becomes a biomass plant fueled by Portland's pug shit.