On the other hand, if they do walk to the desk, by the time they reach the desk, they pretty much forgotten what they tried and they become very passive when I show them how to search. Obviously, I very much prefer the later type of interactions.
Today, I had two really good interactions. One of the users was really curious when I showed her how to find a relevant book and then use LC subject headings to browse and I explained the concept of subject browsing. It's really enlightening to remember that in this day of Google, many of our users have no concept of subject browse, to them using keywords to search is the only technique they have in their own tool-kit. After explaining to her the reason for controlled vocabulary, she curiously asked me who were the librarians who sat around all day, assigning subject headings? :) They are called catalogers....
To make matters interesting, I was also conducting a class to about a dozen librarians on how to do chat duty in the afternoon! This is the 2nd run of four sessions I would eventually do this month.
This does not mean I am a very good trainer, not by the long shot! Though this year, I got smart and divided classes into classes with librarians who had Instant Messenging experience (if only on a personal basis) and those who did not and were unsure even about the concept of IM, hence needed more hand-holding.