As a kid, I always wanted to put a message in a bottle and throw it in the ocean for someone in a faraway land to discover. I thought it would be cool to see where and how far it traveled. Since I didn't live near the ocean, I had to come up with a plan B.
Plan B was put into action when I came home from the local county fair with a helium balloon. I attached a self-addressed postcard and a string to the balloon, but the postcard was too heavy. I ended up making a light weight postcard out of thin typing paper. I added labels to the postcard for the recipient to fill in their name, age, address and the location where they found the balloon, and I wrapped it with plastic wrap to keep the paper dry. I had to trim the size of the postcard a few times before it seemed air worthy, and then I finally let it go.
The postcard arrive in the mail about a week later. A thirteen year old girl in a nearby town found the balloon. My father estimated that the faraway lands that I dreamed of were in fact about seven miles away.
About thirty years later, I noticed that I had a dollar bill with a web address stamped in a couple of places on the bill: http://www.wheresgeorge.com/.
The Where's George? site allows you to register bills using the series and serial numbers, and you will receive e-mail notifications when anyone else registers any of the same bills that you registered. Each e-mail includes a link to a page on the site that shows you the registration log for the bill, the distance traveled and a map showing the path that the bill took based on the log entries.
I always log any bills that I find stamped with the http://www.wheresgeorge.com/ address, and I have occasionally written the address on a bill.
Below are some screen shots showing logs of bills that someone registered after I had. One made it all the way from Martinsburg, WV to D.C. by way of Bowie. The other made it from Bowie to Bristol, NH in eleven months.