Lots of people have an instant messager connection open all the time. It would be nice if one of your IM buddies could be your local library, and if that library bot could answer a bunch of questions. Better still would be if this library bot could have code that was shared among a bunch of libraries so that even though they are all using different catalog software there's a common language and design and command set and shared development so that patrons of libraries without programmers could still take part.
Here's the pieces parts, some of which I'm missing.
1. Pick an IM protocol that supports bots and that supports your library users. An obvious one would be AIM, but there's also Jabber for Google Talk users and Yahoo messenger.
2. Define a command language. This might be the hardest part. I'll guess I start with "books" to do a keyword search on the collection and "hours" to tell me when the branches are open. There should be more. You'll need a little tiny command parser for this one.
3. Interface with the catalog. The easiest and most portable way to do this is via RSS, no surprise, because it hides all the library goo and just gives you easy to parse data back.
I'm working away on the third part of this - just sent off a patch to DuckyTool to wrap a keyword search of the AADL catalog. That gets back plain text results which I should be able to feed upstream.