true, in a debate a few years back i argued strongly against ethanol, using Brazil as an example of how stupid it can be. The thing is we arent looking for perpetual energy here, all we need is a source of energy that will be cheaper than petrol.
Hydrogen fuel cells might work,but your same response is true because if you put about $1 of electricity into a fuel cell, you will only get say 90c of energy back out. The point is that not everyone has a coal power plant strapped to their car, so we need an efficient way to transport electricity to mobile uses.
Ethanol on its own is not the answer, and personally i beleive that alternative energy is not the way, we should be looking to secure oil reserves in the middle east to enure out civilisation survives. Its every country for himself, iam just glad in the oil wars we will be on the american side. What happens when even that oil becomes too expensive to extract though? what shall we turn to for energy?