Have you heard of this? I have but have never checked it out! Until today. I pulled a $10 bill out of my wallet that my Grandmother had given me (yes my Grandmother still slips us "kids" money when we see her! HA! Love it!) the other day when she was visiting us for our mini family reunion. Before I had the chance to spend it at lunch the stamp on the back of the bill caught my eye! I plugged in the serial # ect and found out that the bill had been all over the US! Pretty cool huh?