Corn ethanol is what particularly raises my hackles.
* More energy in than energy out (total waste).
* Use of food as fuel.
Why?
If cellulose ethanol (switch grass) were viable today, I might feel differently, but that's not what's going on.
Actually, it looks like I'm a little out of date:
http://blogs.usda.gov/2010/09/21/usd...gy-efficiency/
But maybe that's debatable:
http://en.wikipedia.org/wiki/Corn_ethanol