A green limo is no stretch

"This is a traditional car service," said Fray, who has worked as a professional chauffeur on and off since 1985, "in untraditional cars."

That has caused problems beyond the ridicule of other limo drivers.

Last year, when Fray was taking Theron to a party after an awards event, a West Hollywood sheriff's deputy wouldn't let her park her Prius with the other limos.

"I told him this was a limo, but he said, 'No it's not.' Then Charlize screamed from the back seat, 'This is a limo!'

"The sheriff looked back there to see who yelled. He let us park."

A spin with Ecolimo allows Hollywood figures to be environmentally correct in public even if that's not the case in their private lives.

Ricky Strauss is the president of Participant Productions, the company that co-produced the hit global-warming documentary "An Inconvenient Truth," which featured Gore. Strauss and others in the company took an Ecolimo bio-diesel sport utility vehicle to the Academy Awards in March.

"If everyone started using a bio-diesel SUV, it would make a big difference," Strauss said. "Frankly, it's about doing what we can."

Strauss' own car, however, is an Audi, a sporty German brand that is a favorite in Hollywood.

"But I live only five minutes from the office," he said, "and only fill up once a month."

Sports cars are just a drop in the bucket. The film and television industry is a major polluter, annually spewing 140,000 tons of waste from trucks, special effects and other sources into the Greater Los Angeles atmosphere, according to a UCLA study released in November. Although exact comparisons weren't available, experts said that these emissions probably made the entertainment business the second-worst industrial polluter in the area, trailing only petroleum refineries.

Even so, going eco-friendly at events has become a trend among Hollywood figures, said Sara McLean, publisher of Limousine & Chauffeured Transportation magazine.

"They might not drive an ecological car on their own time," McLean said, "but when they are seen at an event, they want to be branded as cool."

Ecolimo also gets business from people who want to impress the environmentally minded in the industry. Weather Channel executive Marla Hoppenfeld took an Ecolimo car to oversee a video shoot at the home of eco-activist Laurie David.

"I wasn't about to show up in a town car," Hoppenfeld said.