Reference by walking around
(pointed out by KP on the CLIS list
Like management by walking around... or as I used to call it, guerilla reference, Texas A&M equiped their guerilla librarians with tablet PCs as reported by Smith and Pietraszewski ("Enabling the roving reference librarian: wireless access with tablet PCs" Reference Services Review
v32 n3 (2004):249-255. DOI: 10.1108/00907320410553650).
I like this idea, but of course it's expensive to start and do if you don't already have tablet PCs and wireless.