The jingle, “I love what you do for me, Toyota!”, rings true for the carmakers' environmentally conscious customers, as Prius sales reached the one million mark last week.

What started as an experiment in automobile technology became the first mass-produced gas-electric hybrid to exceed sales expectations.

The Associated Press reports that of Prius sales worldwide, 592,000 were in North America and 315,000 in Japan. Toyota (TM) predicts that by the end of April, a total of 1,028,000 Priuses -- the company’s top-selling hybrid -- will be sold in 40 different countries and regions.

As more green drivers take the wheel, Toyota plans to increase output with a goal of selling one million hybrids annually sometime after 2010.

According to Toyota, the “introduction of the Prius has resulted in 4.5 million metric tons less of global warming gases compared with having standard gas engine cars on the road.”

By alternating between a gas engine and an electric motor, and recycling energy as it moves, hybrids produce less emissions than a traditional car.

For stop-and-go city driving, the latest Prius beats standard cars, delivering an estimated 48 miles per gallon. On highways it gets 45 miles to the gallon.

Like Toyota, Nissan (NSANY) plans to capitalize on peak hybrid sales with a joint venture with NEC to develop advanced lithium-ion batteries for electric and hybrid cars.

Now that "going green" is chic it's possible for ornery, bespectacled bald men to become de facto spokesmen for the cause. That's not such great news if you look like Fabio, but for Prius-driving Larry David it's pretty good. Pretty, pretty, pretty good.