Pinterest is a great site. I have used it personally (is wedding planning too cliche a use?) and professionally. For my students, although I honestly don't know how many have accessed the page, I try to use it for reading promotion. I have set up boards on my GVLMC account for One Book, One School (Maze Runner) and reading lists for chemistry, summer reading, and various award winners. I have also added fun library pictures, book art images, and children's literature.
How are you using Pinterest in your library?