Can Biofuels be an Alternative to Oil?

The Gulf oil spill has shown humans helpless in the face of an ecological disaster stemming from the search for more and more oil. But what are the alternatives for the U.S. …-- a country that every day uses a quarter of the oil consumed worldwide -- two-thirds of that oil used for transportation. Clean Skies' Margaret Ryan reports on what else is available to fuel the vehicles we depend on.