I'm one of the few New Yorkers who is relatively uninterested in real estate, but even I found Zillow.com to be hopelessly addictive. Type in your address—or any address—and you can see a satellite picture of the home, a current estimate of its value, a history of price changes over the past one- or five-year period, prices of all the other houses in the neighborhood, facts about square footage and when it was built, etc., etc. It probably doesn't have much information about, say, Saugatuck, Michigan, but if you live in the Bay Area or New York City, my guess is that you'll find this site almost pornographically fascinating.