i've picked up some fun $1 serials in the last month. i have: 2006 L 66616661 B 2006 A 66666679 F 2006 D 00000571 G they're all from circulation, so all kinda beat-up, but still fun!
If anybody finds a serial number with the first digits of pi (any combination can be found in pi and there is no end, so only the first) I would pay a handsome price for it. I won the pi memorization contest at my school, 161 digits and it only took me about an hour, I wasn't even expecting to win, I just did it because my friend mentioned it at lunch, but it would mean a lot to me to have a pi serial number - that is 31415926 or 31415927
Well I for one like it! If it's the coolest serial you've found, KEEP IT. At least keep it until you've found one more cool.
It's like playing a scratch off lottery ticket, you scratch away the first few all revealing 1 million and then the last one is different...