Hybrids are kinda funny, since they only use about a third of the battery capacity. In other words, they charge the battery to two-thirds full, and only drain down to one-third. But, there is a small group who have modified hybrids into “tri-brids”, so they charge them at home and work, and run them 10-90, and get more capacity.

Battery cost and recycling are issues with hybrids. The batteries are large enough so they are economic for recycling, and the toxic metals don't wind up in landfills.

At 2 bucks a gallon, hybrids aren't economic, but at 3 bucks they are. (rough calculation)
Plus government subsidies, and things like carpool lane stickers shift the economic curve.

Diesel engines are more efficient than gas engines, and they are finally scaling down the pollution stuff to fit smaller engines (like in cars). They don't pass now, but next year's Mercedes diesel passes, and VW can't be far behind. (Mercedes is good about licensing technology to other companies). Chrysler (Mercedes) is close and Ford and GM are last to get a pass.

Biodiesel (ethanol mix) is a future option

Interesting info on the hybrids, thanks Mike. I am very interested in the prospect of bio-diesel — diesel as a clean, alternative fuel is one of my pet interests.

Yeah, biodiesel is a good option. Basically, about half our oil is imported. And two thirds of our oil is used for transportation. By cutting our use of oil for transportation, by three fourths, we wind up needing no imported oil.

We don't have to cut transportation by 3/4, we just have to cut oil by 3/4. Most of America lives in cities and suburbia, only 15 percent live in rural areas, or in/near small cities (15,000 people - the basic county seat). Those people can go biodiesel or bio-gasoline (E-85, etc.) and reduce oil by 50 percent, or so. Same cars, pickup trucks, etc.

In cities/suburbia, a whole new category of car is needed (they already exist in Europe and Japan) that is Geo-size, and travels in smaller lanes, on lighter bridges, etc. Pretty much, if you want to commute solo, you use one of these 40 mpg critters. They can be hybrid, or electric, too.

Generally, the worst one percent of the drivers waste about 3 percent of the fuel. By worst I mean violations and rudeness. Substantially reducing this population, and keeping them off the roads at prime time saves everyone a bunch of fuel and money.

Most over the road trucks and containers can go by rail, for most of the trip.

Aviation consumes a small amount, but turboprops can replace (pure) jets on half the routes. The sky only holds 5000 jet planes, the turboprops can pick up the growth.