Forget Digging For Coins- Look At The Bills In Your Wallet

http://coolserialnumbers.com/default.aspx

Unusual' bills are being bought, sold and hunted on the website Cool Serial Numbers.com,  with low serial numbers, from 00000001 to 00000100, being particularly sought after, a $1 bill with the serial number 00000002 going for $2,500.

The U.S. based site lists all the different notes that collectors are looking out for and allows serial number fans to get in touch with one another.

There are categories such as 'solids' (where the digits repeat eight times), 'ladders' (12345678), 'radars' (01133110 - where the number reads the same left-to-right as right-to-left) and 'repeaters' (20012001 - the second half is the same as the first half).

A $5 bill with the number 33333333 is currently up for sale for $13,000, while a set of nine $20 bills running from 00000010 through to 00000090 can be bought for $1,800.