USPS pilot flex fuel program ...

Although the headline of this article is incorrect, there is good information:

Link

1) Different alternative fuels are going to work in different regions - ethanol will be plentiful in the midwest.

2) Ethanol's purpose is to reduce dependence on foreign oil, not see an enormous boost in efficiency and / or save a lot of money.

I am glad all these approaches are actually being tried out - it helps generate real numbers for comparison purposes.