Quote: On Bicycle
Pound for pound, a person on a bicycle expends less energy than any creature or machine covering the same distance. A human walking spends about three times as much energy per pound; even a salmon swimming spends about twice as much.From the book Stuff: The Secret Lives of Everyday Things
(found via TreeHugger)
Update 28 Aug: Excellent post on "How to Ride Your Bike to Work".