Via BS, from Do the Math MPG of a Human :
"On Do the Math, three previous posts have focused on transportation efficiency of gasoline cars, electric cars, and on the practicalities of solar-powered cars. What about personal-powered transport—namely, walking and biking? After stuffing myself over Thanksgiving, I am curious to know how potent human fuel can be. How many miles per gallon do we get as our own engines of transportation?"
Businessweek: The Gas Station of the Future Just Opened
"‘Our conclusion is that natural gas as a transportation fuel has both adequate abundance and cost advantages that make a strong case to focus interest in the technology as a real game changer in US energy security,’ said Mike Duoba, an engineer at the auto research center at Argonne National Laboratory near Chicago, Illinois."