A new study in the Journal of Computer Mediated Communication has some results that those of us who use instant messaging already knew: Instant messaging proves useful in reducing workplace interruption
...research showed that instant messaging was often used as a substitute for other, more disruptive forms of communication such as the telephone, e-mail, and face-to-face conversations. Using instant messaging led to more conversations on the computer, but the conversations were briefer, said R. Kelly Garrett, co-author of the study and assistant professor of communication at Ohio State.
I don't think that is anything earth shattering, but it certainly provides some research-based evidence that use of IM can improve productivity.
I went to find the actual research article and it has not been posted: Journal of Computer Mediated Communication. This research is to appear in the July issue and the latest issue listed on the site is for April. Oh well, they were getting a little ahead of themselves with the press release. Guess I shouldn't worry about a few days. The actual research was conducted back in 2006. That seems like a long time ago seeing as how fast this stuff is moving.