The Insultingly Stupid Movie Physics site is a real pleasure to peruse. All those action movies, they've got it wrong. My fave: you know when the bad guy/hero uses a cigarette to light a puddle of gasoline? Doesn't work. The tip of the cigarette just isn't hot enough to ignite the fumes -- of course it's the fumes not the liquid that burns. The liquid gas actually puts the cigarette out! via Now Magazine.