This is pretty cool
I got a dollar bill in my change at Cedar Point yesterday that had the website www.whereisgeorge.com stamped on it, so when I got home, I looked it up. It asks you for the serial # on the bill, the zip code where you are and any other info about it and then shows you the history of this same bill that others have filled in. Kind of clever. This is the link to the bill I found:
http://www.wheresgeorge.com/report.php?key=c9ab91d93cc10e435b376ba75b433a41