This might be the most disgusting use of green technology I've ever seen, but yes, Norweigan fecal matter will keep their Buses up and running.
According to Worldchanging, the City of Oslo will convert the sewage to biomethane, then get that methane working as bus fuel. Two sewage plants in Oslo will be adapted to support the infrastructure and the 80 buses will require minor modifications.
The Oslo Sewage Bus trial is expected to begin in September, and if successful, all 400 Oslo buses will be converted.Putting aside initial costs, the biomethane is expected to be about €0.40 cheaper per litre, and each bus will save about 40 tons of carbon dioxide every year. [Worldchanging via Earth First via Slashdot]