Have signed up for linkedin . The site doesn't recognise @bodleian for making connections with others. Tried @ymail and saw a few familiar names.

Becoming a fan on Facebook seems to be popular. Facebook allows libraries to give information in a more informal and welcoming style - e.g.we're a 5 to 10 minute walk away from..blah blah. It gives individual libraries a chance to be more creative and also to engage in discussions with users about their needs. The photos help users to find their way around the library and to see the extent of the services available before visiting. (However ... I think it's generally accepted now that students prefer to keep their online 'work' lives separate from their online 'social' lives).
Bodleian Law Library - 176 fans
Education Library - 269 fans
Harris Manchester College - 112 fans
English Faculty Library - requires log-in
Language Centre Library - 93 fans
Linacre College Library - requires log-in
Nuffield College Library - 209 fans
Oriental Institute Library - 55 fans
Queen's College Library - 1,987 fans
Sainsbury Library - 66 fans
St. Hugh's College Library - 154 fans
Vere Harmsworth Library - 67 fans
The British Library - 6,869 fans
National Library of Scotland - 625 fans
The Library, Birkbeck, University of London - 424 fans
The National Library of Wales/Llyfrgell Genedlaethol Cymru - 358 fans
Trinity College Library Dublin (TCD) - 314 fans

Subscribing to podcasts using Google reader is straightforward. BBC site is an obvious choice as well as JISC - I appreciate their short duration (~10 mins), useful for keeping up-to-date.
YouTube is first choice for music videos. I had a look at the YouTube video tutorials for step-by-step help with Google reader.