Some enterprising soul has designed JungleScan, a sort of stock ticker for Amazon products. It enables you to track the sales ranking of a book over time. So, for example, you can see how UML for Java Programmers has (inexplicably) grown in popularity by 689%. This is all possible because Amazon, in a fairly uncorporate move, much of their database and programmatical content to the world.
This came from Neil Gaiman’s site, where he discusses tracking one of his books. He also talks about being stalked in Finland…what a strange life he must have.