anyone else here participate on wheresgeorge.com? it's my geeky hobby. you enter the serial numbers on paper money, mark them with the URL, spend it or whatever, and whoever else finds it can enter the serial number, kind of like keeping track of where your money goes. i've been doing it for 3.5 years or so. i've entered 531 bills, and have gotten a total of 50 hits. below is a link to my "hit map". red counties are where i've gotten 1 hit, blue are more than one.
County Hit Map