I had a sit down last week with a librarian working closely on an IM Reference project. I asked what kind of IM interactions they get at their library. She had this list, which may be similar to what other libraries have encountered as they begin projects like this.
* Kids seeing if someone is actually "there"
* A few questions of the "Are you hot?" variety
* A lot of informational questions about the library: hours, etc
* Some gosh darn spiffy* reference questions
I think it's important for training to understand we may get a few questions like the first couple. It does not mean that all IM is all about "What are you wearing?" but that we can handle those as well:
Response: "A sensible shirt and trousers, but the more important question is , can I help you with a question about the library today?"