A few comments

Google diary: I notice the UL is running two diaries which you can find on its home page. The Google diary in the 'Library toolkit' suggests that the Spies exhibition is still running.
Facebook - if an organisation has a Facebook page, then really it needs to be active - something appearing at least every week. The Cambridge Libraries page hasn't had anything added to it since 3 May. That makes it easy to forget about. It seems to me that the Orkney Libraries on line presence is successful because library staff are busy putting things on it.
LinkedIn - the Darwin project is being pestered by someone who wants to be linked to it. But the darwin Project isn't LinkedIn.

Thing 17

LinkedIn. I have found this several times while researching people on the internet, and it was interesting to see the whole of it, rather than the little bits I'd come across before. Usually I'm researching dead people, so I discount any hits in Limekiln. It seems so like Facebook that I'm not in a hurry to create a page for myself: these pages need to be looked after and in the end it all takes time.