Found this poster on a guide to money on the xkcd site. It started as a project to understand taxes and government spending, and turned into a rather extensive research project. It goes through from Dollars – Thousands – Millions – Billions – Trillions. The 36″x24″ high-quality poster print allows you to stand back and, all at once, take in the entire world economy. Below is the part on Trillions. To order go to the store.