I got a dollar bill the other day had a red stamp on it saying it was a registered bill and it had wheresgeorge URL on it. People can register and enter bills and then follow their progress.
I browsed around and found a dollar bill that had travelled 4,119 miles in a bit over 3 years through 15 hands - it was the most frequent traveller.
And then there is Wattsburg Gary who has entered 439,560 bills into the database. He is a gunshop owner who says he enters bills in his spare time. I guess a lot of cash goes through his hands and he has a lot of spare time. He's been doing it since Jan 15, 2002.
The web site says they have 79,659,750 bills being tracked!
Amazing, and I don't think I've ever seen one of these bills before.