File this under “markets in everything”: people will pay big money for US currency notes with interesting serial numbers.
In addition to the “low numbers,” which stop at 100, there are “ladders,” which have numbers in sequence, such as 12345678 or 54321098. These sell for as much as $1,300. A “radar” (selling for $20 to $40) is a palindrome, such as 35299253, and “repeaters” are notes with two blocks of the same four digits, like 41884188. Undis observes subcategories of each of these, such as “super radars” ($75 to $100) that have all internal digits the same, like 46666664.
And here I thought I was being pretty eagle-eyed by fishing a $2 bill out of the tip jar at the bagel place this morning. (via digg)