But all hybrids are not created equal. Compared to the Honda Civic hybrid, the Toyota Prius has a smaller gasoline engine and a much larger electric motor, which is connected to the drivetrain in a different way. This gives it significantly higher mileage, especially in the city.
And now Honda is coming out with an Accord "hybrid" that has a huge 3.0 liter V-6(!!!) engine, plus a small electric motor that improves acceleration and fuel efficiency somewhat. I wonder if this 255 hp car will be allowed to use the carpool lanes, while more fuel efficient cars like the conventional Civic are shut out. According to the WaPo story, the "hybrid exemption is scheduled to expire in June 2006, and the HOV task force of Virginia transportation officials and experts urged...that state leaders not extend it."
And some people question whether hybrids are really any better for the environment at all (an opinion which I am not qualified to evalulate).
Zywicki also links to this classic Onion article: "Report: 98 Percent of Commuters Favor Public Transportation For Others"