Numbers: A milllion here, a million there, pretty soon it adds up to real money

'Visualizing huge numbers can be very difficult. People regularly talk about millions of miles, billions of bytes, or trillions of dollars, yet it's still hard to grasp just how much a "billion" really is. The MegaPenny Project aims to help by taking one small everyday item, the U.S. penny, and building on that to answer the question: "What would a billion (or a trillion) pennies look like?' -- from the website. <http://kokogiak.com/megapenny/>