I had a dream last night that someone had figured out how to store data on quarters (like a disk) by magnetizing the metal in different ways. Everyone had these little quarter drives that you could use to read the data. And when you purchased something with a quarter, part of the space was used to store data about the transaction. So you could go back and track what exactly that quarter had been used to purchase. Which seems silly because what can you buy for a quarter besides gumballs and parking?