The next time you're holding a dollar bill, it might be worth looking further than the big number one - you could get more bang from your buck than you expected.Ordinary low denomination bills are raking in thousands of dollars in an online trend that is centred on the eight-digit serial number which appears on each U.S. banknote.

'Unusual' bills are being bought, sold and hunted on the website CoolSerialNumbers.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).

Then there are 'radar repeaters' (12211221), 'super radars' (20000002 - all the internal digits are the same) and 'super repeaters' (where the first two digits are repeated four times, such as 63636363).

Dave Undis, the a Nashville musician and currency collector who runs the site, is happy to include some criteria that might go unnoticed to the untrained eye - such as a 'pi note' with the number 31415927.

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.

Collectors have long been interested in rare and flawed money - and not just in the U.S.

In September last year, the Bank of England auctioned £5, £10, £20 and £50 notes with unusual serial numbers - such as those coming at the beginning or the end of a run, often characterised by the prefix A01.

To read the complete article, see:Is your dollar bill worth thousands? The bizarre trend for collecting cash with 'interesting' serial codes(www.dailymail.co.uk/news/article-2423315/Dollar-Serial-numbers-make-banknotes-worth-thousands-online-trend.html)

To read the complete article, see:For serial-number hunters, $100 isn't just $100(www.boston.com/2013/09/15/dollars/C0qw9KcJvAmWwGyVWqREOJ/singlepage.html)