In case you were wondering what goods Google has on you check out http://www.google.com/ads/preferences/ from the browser you typically use for web browsing and search. If you scroll down you’ll see what interests Google has you pegged for and get to see the data they have collected on you in your cookie.
For me the most interesting part wasn’t the data they had on me, but looking through the Google interests taxonomy at the bottom of the page. There are specific tags for individual car brands, for your love of Bollywood movies, pest control, screensavers, etc. It’s an interesting glimpse into how Google thinks about the world (and more importantly into what categories Google thinks it can make money by trafficking).