One of the websites I used way back in 1998 was Where’s George? The site is still active and it allows users to track the travels of a particular piece of U.S. paper currency.
Users (called “Georgers”) write or stamp “www.wheresgeorge.com” onto their bills and then release them (well, spend them) into circulation. Then you hope that the next user will visit the site and log in your bill’s new location.
Bills receive “hits” each time someone logs a bill they have registered. You can even compete for “George scores” (based on the number of bills and total hits), and play “bingo” by attempting to register hits from every state.
I started using the site with students as a little project and they really got into it. Well, they enjoyed the initial surge, but they lost interest when their bills stalled in a location because the next owner didn’t bother to log in.
There are also sites in Germany (Wo Ist Mein Geld — Where’s My Money?), Japan (Osatsu — bill), and Canada (Where’s Willy?).
Is this “currency defacement” – a crime? The Bureau of Engraving and Printing defines illegal defacement as “mutilation with the intent to render the bill unfit for reissue” – so I guess doing the George thing is acceptable.