Yelp.com is an online social networking site where users can write reviews on local businesses and government services. I learned about it on the Librarian in Black Blog.
Here is what they write about themselves.
...the ultimate city guide that taps into the community's voice and reveals honest and current insights on local businesses and services on everything from martinis to mechanics.
As advised on the Librarian in Black blog, I did a search using the term library with the zip code 76109 and received several possibilities, including one for North Texas Regional Library System. No one had written reviews for any of the NTRLS libraries. What a great, easy way to collect feedback on your library. The service is at no cost and if your patrons start to write reviews, you might receive some helpful feedback on how to improve your library.
Now all we need is someone to create a online social networksing site exclusively for library reviews. What a boon of data that would be!