Where's George ?!
I have a silly confession -- I like www.WheresGeorge.com. I guess it makes sense because I like spending quality time with my money.
I take a bright Sharpie (usually fuschia) and write along the top www.wheresgeorge.com and enter it into the Where's George database. It's interesting to see the travels your money will take when someone takes the time to enter the bill when it reaches them.
Give it a try!