Sales of hybrid vehicles jumped 140 percent in the past year, and auto manufacturers have finally gotten off their tuchuses and taken notice. More and more models are being offered with hybrid power plants, and many more will be coming in the next few years.

Whether consumer demand will keep pace with the increasing supply isn't known. Much depends upon the price of a gallon of gas in the coming years and whether other, better technologies emerge and mature.

While the first few hybrids to reach the U.S. market, the Prius and Honda's Insight, were designed as hybrids from the ground up, the trend now is to add hybrid technology to existing models — the Honda Accord, Toyota Highlander, and the Ford Escape, for example. In a few years, it may be just another engine option. The salesman may ask you, "Would you like the four-cylinder, the six-cylinder, or the hybrid? OK, how about a five-year protection plan for your fuzzy dice?"

We'd take this increasing availability as a sign that the technology is maturing, and owning a hybrid no longer puts you in with the pocket-protector-wearing, recumbent-bicycle set. Hybrids no longer call attention to themselves, and drive pretty much like any other vehicle.

Hybrids are proof that you can have your tofu cake and eat it, too. Once you've swallowed the purchase price premium, it's a relatively painless way to do your part to reduce your impact on the planet — and save on gas costs, too.

On to How Hybrids Work