The first post I looked at was www.librariesyes.com  The were trying to make sure you voted yes to save the Multnomah County Libraries.  They posted pics of their patrons holding a big heart that said My Library.  The second one I found was for warner.edu it showed lots of pics on what the library is doing, its patrons, its book displays and other library pics.  I think instagram will be a great asset to a library because a picture is worth a thousand words.