Before choosing to take the optional adventure and create my own Facebook account I never thought there was much point to any of these social networks, why can't people meet in person or pick up a phone if they want to talk. I am now an advocate for Facebook, what an experience I created an account and typed in the name of my high school and dates that I attended and wallup there in front of me was half a dozen people I had gone to school with twenty odd years ago waiting for me to contact them.
I can now see how these Social networks could be used in a library, we could have links from our webpage for various subject FaceBooks such as a Genealogy Facebook for users to share information and help each other. Non-English language Facebooks (eg German, Japanese) as within our community we have clients from diverse ethnic and cultural backgrounds.
I have noticed within our library that the senior clientele seem to embrace new technology, I think if we teach them how to use these social networks they will enjoy using them.
I must admit I am not a big fan of wikis for larger libraries, I did enjoy looking at St Josephs County Library wikis, but it got very confusing navigating through the different links. Saying that though libraries could use wikis for advertising new books, organisations could advertise events on a virtual community notice board, and the public could contribute helpful information for family history.