I admit, I have been having a hard time trying to figure out how to use twitter in a useful way at the library.
So far the best public use idea is to post "tweets" of titles around a genre, say British Mysteries. Then ask the public (followers in twitter lingo) to reply back with their favorite titles in that genre. We would end up with a list of titles, that may serve as recommended titles to other followers as we follow each other or retrospectively search the twitter-verse for the genre of the week.
The best idea so far for use by library staff is as a replacement for our IM clients on the staff machines. If all the branches followed all the other branches on twitter, they would all see the same question or request at the same time. With IM, its a one to one communication, twitter would allow one to many communication. The assumption would be that the branch that coudl answer the request first would do so, thereby fulfilling the customer's request faster.
What do you think of twitter in the library? Is it just one of those technologies that just don't jive enough with the work of the library?