There was an excellent article in Bloomberg magazine about ethanol companies.
I would hold on a while though.
The US government in their ultimate wisdom and care for the environment have placed large tariffs on countries like Brazil on their ethanol imports. Viva free markets and the capitalist system eh America? NOT! (Just another one of a wide number of hypocrisies that is modern America)
Currently, 75% of Brazilian cars already run on ethanol, and it is the worlds largest producer of ethanol and sugar - the core ingredient.
If oil drops though, the ethanol market will get flattened, so tread carefully!