The Dec/Jan 2008 issue of the Bulletin of the American Society for Information Science and Technology is mainly about virtual reference.
Virtual Reference Services
6] Introduction by Yungrang Laura Cheng, Guest Editor
8] An Informal History (and Possible Future) of Digital Reference by Joseph Janes
11] Virtual Reference to Participatory Librarianship: Expanding the Conversation
by R. David Lankes
15] Evaluation of Online Reference Services by Jeffrey Pomerantz
20] Implementation of Professional and Ethical Standards
by Pnina Shachaf
25] On the Trail of the Elusive Non-User: What Research in Virtual Reference
Environments Reveals by Lynn Silipigni Connaway, Marie L. Radford and Timothy J. Dickey