I work at a college, so *of course* I know about facebook! i started a facebook account when my students would never return emails. If I posted something on their wall, or saw that they were online, I could message them "get in here! you were supposed to be to work 10 minutes ago" Heh!
I started a "group" for Quatrefoil library (http://www.facebook.com/group.php?gid=18817789576) and use it for posting events, announcements, and reaching people on our email list. I use the librarything.com tools to post recently received books. I'm added the visual bookshelf app, and the "Things I read" to get other recommendations and suggestions. I was hoping more members would post to the bulletin board and post book reviews, but....soon.
I also created a Page for Quatrefoil, but that seems more like a commercial venture to sell ads to our targeted audience. That is not in our budget right now, so we have not gone forward with that. If we could use the apps on the Page like I can on the Group page then I'd consider it. I have downloaded the API's and during summer break would like to create s facebook book application. Code on!
I had another Q board member push for a mySpace page....sure go for it. And dang if we don't have over 1000 "friends" of the library! Great publicity. Now how can we get those friends into the libary...as members, volunteers, patrons, contributors? I joined to add events and comments, but I thing im a bit older than the myspace demographic. I'll stick to ning & facebook.