I've just realised that I've been terribly remiss and haven't mentioned here a (fairly) recent publication:
Tumelty, N., Kuhn, I., & Birkwood, K. (2012). TeachMeet: Librarians learning from each other. In P. Godwin & J. Parker (Eds.), Information Literacy Beyond Library 2.0 (pp. 191–201). London: Facet Publishing.
In this case study, we present the TeachMeet concept, discuss how we adapted it for use by librarians and consider how this model is spreading beyond Cambridge. In particular, we consider the role social media had in the inspiration for and organisation of these informal peer support events, and in the dissemination of information about the events once they had taken place.
I have submitted the pre-publication version to our institutional repository or you can find the prettier published version in a library near you!