If you haven't checked out the new real estate search website Zillow, I highly recommend it. It aggregates all the public information about home sales and assessments into an easy-to-view map format, so you can see the value of your home growing (or shrinking?) over time. Finally, a website has made this information transparent, instead of locking it away (like 100% of real estate agency websites seem to do)!

Another good one, although it only covers Seattle, is Redfin. This site shows you houses currently on the market along with recently sold houses. Kind of like Zillow, in that it organizes the information on a google-esque satellite map, but here the information is very time relevant. (Via information aesthetics)