In Europe, one billion equals 10^12, this is the Tera (like for hard drive capacities) prefix in large numbers. The US uses trillion for 10^12, but this would really shock the people. With the current US national dept exceeding the 14.46 * 10^12 USD reported in 2011, there are plans to make a coin like this of platinum as security for additional funding. Here you can have your own, for a much cheaper price, in gold plated brass. Of course, it's not really worth that much (like the platinum thing). You could even get the plastic versions, they are MUCH cheaper than the real thing would be. The cheapest version is the downloadable one, go for that if you're not of the materialistic type or can't/ won't spend the money for such luxuries. The downloadable version lurks here, find it as soon as Shapeways has fixed the seach engine.
Update: US dept ceiling was 16.394*10^12 USD