Imagine pulling up to a filling station, inserting the nozzle into the tank and the gas flowing into your tank is ... hydrogen. Its colorless, odorless and the byproduct of burning hydrogen is water vapor, quickly and safely absorbed by the environment. One pound of hydrogen supplies three times as much energy as a pound of gasoline. And its the most plentiful element in the universe No wonder scientists are trying to figure out how to make hydrogen work as a practical fuel .

Website: http://science.nasa.gov/headlines/y2003/17apr_zeolite.htm?list801859