We had some late night visitors from Zack's program. I was surprised that I had a couple of people stop by at night (I logged in at 9:30 SL time) all looking for books. There were quite happy with the bookcase and while I was at the library I created a table of contents for the bookcase witch made it easier for people to access and not clutter their inventory with notecards. I also was able to create a little shape that would tell users when I'm online. Anyone who is going to be a SL Reference Librarian may want to do this. I did confuse many people by being on the Second Floor.
I also wanted to add that it helped me to automate gestures for working at the desk. Everytime I though someone was near I could press F2 to greet them while continuing a conversation. Zack mention something similar he used during his presentation.