If you own a house, want to own a house or have ever been in a house, you may want to check out Zillow.com. It's a simple site, really: You type in an address, and it will give you an estimated value, using recent sales and other data.
While some of the values are a bit strange, the site seems fairly accurate. It does a fantastic job of showing that last year's Tucson real estate bubble has at least deflated, if not necessarily burst.
Case in point: My house went down in value by $92 in the last week, so says Zillow. Sigh.