When gas becomes so expensive that alternative forms of energy become competative, the price will come down.
I am doing a news story on a guy who made his own electric car for hardly any money....just used batteries he found around and everything. He is a self-taught electrical engineer...remarkable guy.
He just uses the old junk car to drive around town, but it still saves a ton of money.
There are kits you can get online to try to convert cars to other forms of energy and various devices that are supposed to improve gas mileage, but I wonder if they really work.