Whilst looking around Liz's blog, I also found the following interesting postings:
BTW: Liz is undertaking research to understand how social media is being used in UK HEIs - and you can participate in this survey here
From the lists above it seemed that most of the examples are of the use of YouTube. Twitter and Facebook accounts as external marketing tools - and so the research reminds me a lot of Peter Kim's wiki which, since September 2008, has been gathering examples of social media marketing by corporates.
My own interests and research are focused on gathering specific examples of the ways that organisations (both business and education) are using social media tools to promote, encourage and/or support "learning" (in its widest sense) internally (for own staff and students) as well as externally (for customers and students) - whether it be to encourage a more informal, social approach to learning or to complement and extend more formal, course-based learning approaches. Following Peter Kim's approach (above) I am going to set up a wiki to gather and aggregate examples of social media tools for learning. Let me know - email@example.com - if you'd be interested in contributing. I'll make another posting when it is ready for contributions and viewing
SMIL related resources