Wow, so I've missed a few weeks, but I have a pretty good excuse: I'm on vacation in Upstate New York. Here's a photo of me at Fillmore Glen State Park to prove it. Despite my absence from London, I am continuing with the 23 Things even while I'm away from work, and, thanks to my jet lag, I'm waking up much earlier than everybody else and have found the time to do it.
LinkedIn: I have not had much experience with it before. Now that I've joined and made a couple of connections with my colleagues, I can definitely see why it's so useful. For example, for me, an internet lurker looking forward in my career, LinkedIn allows me to see what others have done to get where they are. Obviously, its design is based around networking, and it creates a great space for communication in a professional online environment that isn't directly connected to an organization.
In terms Web 2.0 applications relation to academic libraries in particular, I think that LinkedIn's appeal is limited to library staff, and not so much to library users. That's not so much a criticism as an observation. LinkedIn's utility is narrow and well defined: it creates a social space for individuals to interact as professionals.
If you want a place for the library to market itself to its users, especially when many of those users are undergraduates, Facebook is a pretty ideal platform. The profile page can tell users basic information (e.g. address, phone number, opening hours etc.), while posting allows the library to inform its followers of news. Also, it creates a really nice space for the library to share relevant links with its followers and to keep up-to-date with other libraries. Many other libraries 'like' other libraries and related organizations, and that gives the libraries' users a window into other resources they may not have known about. One problem with this function is that a library could potentially 'like' lots of other organizations, and all of these profiles are lumped into one place with no labels that might help users browse them. However, most of the library Facebook profiles that I've looked at have limited their likes.
It would be very exciting indeed if City Library created a Facebook profile. I wonder what its profile pic would be...