I just wrote a blog on my website about how Trulia® and Zillow® value homes. In this case, a friend had asked me to look at his both sights as one had valued his home at $515,000 while the other indicated $999,000! In this case I had sold the majority of the homes in the nieghborhood so I had a pretty good handle on the value. This isn't the first time, and it isn't the last that these big national real estate sites post values from Mars.
You can find the blog entry about Trulia® and Zillow® here. Please feel free to re-post in your blog provided you credit and link back to my orignal blog entry.