Have you seen this? www.wheresgeorge.com is an effort to track how cold hard cash is flowing across the country. You simply go to the site, enter the number of a bill into their registry, and it starts tracking. If the next recipient also tags the bill, you can watch your money flow throughout the country.
Here’s a video of why scientists are doing this… it’s a cool story of leveraging data to see how communities interact across the country.