Cow Rumen for Fuel?http://www.biologynews.net/archives/2011/01/27/team_looks_to_the_cow_rumen_for_better_biofuels_enzymes.html

With their complex digestive systems, cows can eat over 150 pounds of plant a day. Scientists have found dozens of unknown microbial enzymes in the cow's rumen. Rumen is the first chamber in a cow's digestive system. Scientists are looking into using these microbial enzymes to fuel things, instead of the sugars in certain foods. This is more cost and time efficient. It will not deplete our food supply, and it will take less time than waiting for the natural sugars in foods to break down.

Personally, I find this fascinating. I am all for finding other usable and cheaper fuel sources. This too, seems environmentally friendly. I also think it is neat when scientists find something new, no matter what it is. Hopefully, within my lifetime we can switch to this for a secondary, if not a first, source of fuel.