This Wired article is about a service for art that works a lot like Pandora does for music. You can take a picture--or describe in words--an art work you like, and it recommends others that share similar traits. Interesting fact: the article claims that art sales are greater than music sales, they just are among a much smaller group of people.
I've documented a few examples of artists using money--either literally or in representation--as their subject. John Baldessari joins the game with this billboard on the High Line. The $100,000 bill was actually printed, but never circulated.