I looked at Zillow.com for this activity.
According to their website:
Zillow.com is an online real estate service dedicated to helping you get an edge in real estate by providing you with valuable tools and information.
I thought it was intriguing to see the maps with all the real estate information on them. I looked up my house in Duluth and my parents in Redondo Beach, CA. I found their house had more information about it than my house did. Probably more information available.
I don't see any useful application to this website to the library, except for referring people to it. I did have one person who wanted to know how much a house sold for. The information might be available on Zillow.com
I will definitely use that if I ever think about moving or if I'm just curious about what a house sold for.