wheresgeorge.com
This is a complete aside, but I found out today about a very interesting website Where’s George?!. The idea is to track the path of US Currency. It does it through the cooperation of averages Joes who enter their current zipcode and the serial numbers of the money they have on them. When future people do the same thing, one can see where the money they spent has gone. In some cases it can be very surprising like this one that made it from Ohio to Kentuky to Tennesse to Florida to Texas to Utah to Michigan over the course of 3 years. They’ve tracked (at one point or another 76 million bills totaling $430 million.
Pretty interesting stuff if you ask me.