To find this cache, you must find the right cash: a dollar bill
(or any US currency denomination - $5, $10, $20, etc) that has a
serial number with the eight digits of the serial number either all
odd numbers or all even numbers. Then get a black and white picture
of the bill's serial number with a piece of paper with your caching
name written on it to post with your log.
Once you have the cash, the difficulty is only about 1.5
To log your find, you need to post a black and white picture of the
bill's serial number with a piece of paper with your caching name
written on it.
*** be sure it is a b/w photo zoomed to at least 150%
size ***
Here are the US Government laws about photos of US currency.
http://www.ustreas.gov/usss/money_illustrations.shtml
Photos and logs not in compliance with these laws will be
deleted.
A free, online image resizing tool (and converter to B/W) is
available at http://www.resizr.com/
Group finds are OK if each member of the group has their own unique
piece of cash fitting the requirements (in other words, different
serial numbers).
I had this idea for a while, but needed to find the right cash to
take a picture of. It took a few weeks of staring at each bill I
received before I hit the right combination. See the attached
photo.
Container is a small, but big enough to carry small coins or
tradeables.
First To Find prize is dollar bill with all even numbers (not the
one shown below).
Good luck!

*** congratulations to Keenan Crew on the FTF in less than
45 minutes ***