From the US PopSci team

Aggressive driving -- lead-footed acceleration, speeding, excessive braking -- can slash highway fuel economy by 33 percent, according to estimates. Honda's Insight hybrid, arriving in the US in April, softens the effects of wasteful driving and tells you when you're indulging in bad habits. Powered by a 1.3-liter, 88-horsepower gas engine and a 13-horsepower electric motor, the car saved the US PopSci team plenty of fuel, even when they were ignoring its warnings.

Fuel economy shot up when they engaged the car's three gas-saving features. Australians will have to wait a while longer to get their hands on the Insight, having to rely on the Toyota Prius or Honda Civic Hybrid in the meantime for green driving. While you wait though, check out this Insight video from the US PopSci team.