From National Geographic peeps comes a great multimedia piece on alternative energy. “Biofuels Compared” interactively illustrates how emerging biofuels size up and the benefits and costs of producing each one. It also shows comparison of each source’s greenhouse gas emissions and energy balance (ratio of the amount of fossil fuel required to make each biofuel to the amount of energy the biofuel itself can produce). Naturally, it uses gasoline cost and output as benchmarks. Concise audio commentary provided on each source rounds out the snapshot analysis.