As much as I am upset at BP, I think the American consumer needs to pay too. We need to tax gas to incentivize people to buy more efficient vehicles and fund alternate energy. Yes, windmills are expensive.
Your proposal sound great on the surface but I am afraid that there might be a little sinister unforeseen consequences bubbling beneath. We shouldn't stop at the obvious benefit, but also explore the not-so-obvious consequences.
Tax it enough to make up for those shifted costs, and you won't need to specifically fund alternative energy, as the free market will do that for us.
It raise the cost of fertilizer, plastics, lubricants, paints and other items essential to the modern economy.
It is also not necessary true that we will found a suitable or superior alternatives for each and every use of oils.(Which is a lot by the way)
P.S. I realized that the OP was talking about a limited tax on gas. But even so, people can just switch to disel and disel engines?