Update: Alan sez, "it seems to me the point of these methods should be to reduce the amount of force required to open the jar, and to do so safely. One technique that works for me: use a butter knife, spoon, or flat-head screwdriver to pry the side of the jar lid away from the jar out just enough to break the seal. You will probably hear the air escaping from the jar as you do this. the lid can then be unscrewed almost effortlessly."
I write books. My latest is a YA science fiction novel called Homeland (it's the sequel to Little Brother). More books: Rapture of the Nerds (a novel, with Charlie Stross); With a Little Help (short stories); and The Great Big Beautiful Tomorrow (novella and nonfic). I speak all over the place and I tweet and tumble, too.