This is just a quick post on my lunch break. I just found this excellent post on The Dough Roller, regarding alternatives to Zillow.
Shows you what I know. Apparently there are several other sites that offer free appraisal tools for your house. I tried a couple and none were as simple to use or offered as many features as Zillow, but interestingly, they all offered different appraisals for our house.
Anyway, check out those sites and be sure to check out The Dough Roller while you are at it. It's a good blog.