From a person named Armory Lovins, here is an idea Kevin is highlighting:
For cars, the most effective thing would be a "feebate": In the showroom, less-efficient models would have a corresponding fee, while the more-efficient ones would get a rebate paid for by the fees. That way when choosing what model you want you would pay attention to fuel savings over its whole life, not just the first year or two. It turns out that the automakers can actually make more money this way because they will want to get their cars from the fee zone into the rebate zone by putting in more technology. The technology has a higher profit margin than the rest of the vehicle.
Sounds good to me. But I'm thinking the big oil interests are beginning to fear peak oil and the end of their industry, and have raised prices in their own attempt to get us, the consumers, to decrease oil use. This turns out to increase oil industry profits, with the added benefit to them that it will make their product last a little longer.
To the extent the oil industry is able to successfully lobby Congress and the auto industry, though, the feebate idea won't be implemented, because cheaper-to-drive cars make the oil industry's product actually worth less to it. People won't need as much gas to get where they want to go if people start driving more fuel-efficient cars.
Unless you have a warrant to influence those wily and stubbornly self-centered energy interests, our current problems with gas prices may just be too tough to beat. Those people are just so damn selfish.
Of course, OPEC is as responsible for this as the oil companies are (our government has wrangled with both to try to obtain some relief for American consumers) and it benefits them just as much as it benefits the companies that sell gasoline to extend the life and profits of the industry.
UPDATE: Nuclear power is the answer-- for now.
We've got to go nuclear to keep us going after the oil runs out until we can develop and build a broad alternative energy infrastructure- stuff like windmills and solar power cells everywhere- to (in turn) keep us powered until we have some kind of an energy breakthrough.
This is all going to take place across a period of time that is on the scale of generations, but we've basically got to do it to avoid a Mad Max-like degradation of our civilization. We're already going to head far enough in that direction (that is, the direction of Mad Max anarchy) for anyone's tastes when the oil runs out in 50-70 years (and consumer products consequently become a lot more scarce because petroleum-based plastics are not easy to replace), even if we do build enough nuclear-power generators and electric-powered vehicles in time (that is, in time to avert mass starvation by, when the oil runs out, taking over the train and trucking operations that drag all our food all over the country in refrigerated and non-refrigerated cars).
UPDATE II: I don't really know that the previous estimates we've heard about the onset of peak oil-- 50-70 years from now-- aren't too optimistic, and that the oil companies and OPEC don't know something we all don't. But even if there is still going to be commercially available gasoline and jet-fuel up to 100 years from now, OPEC and the major gasoline producers may have adopted this higher-pricing policy because they are thinking of their grand-kids (or, in the case of OPEC, the future of their nations) and want their loved ones to live privileged lives like they did, rather than have them face the risk of some terrible fate, if oil profits end too quickly.
UPDATE III: What those greedy gasoline companies and greedy OPEC should do with their profits from $4-a-gallon gasoline and $135-a-barrel oil is invest it in constructing new nuclear reactors and developing rewable sources of energy, to help everybody's grand-kids, and the world. But instead, they're using it to cushion up their own piggy-banks. Someone should put pressure on them to become more magnanimous.