Alternate numbering systems: If you're American, you're used to referring to the numbers 10^3, 10^6, 10^9,... as "thousands, millions, billions, trillions, quadrillions, quintillions", etc. But if you're British, you use a different naming system, i.e. "thousands, millions, milliards, billions, billiards, trillions, trilliards", etc. In other words, a "billion" to the British is the same as a "trillion" to an American. (Via BBspot.)