I guess it should be no surprise that the most expensive living artist has very valuable doodles. This was proven recently when Damien Hirst did a little ink sketch on a linen napkin from The Ivy restaurant. It's a depiction of his diamond-encrusted skull, plus a couple of steaming coffee cups in the eye sockets and, of course, the all-important Hirst signature. He donated the sketch to MacMillan Cancer Relief's "coffee art" auction, where it sold to a private collector for £18,000. So do you think it was really just a doodle? Or a creative way to come up with something for the auction?