New report on Twitter and Status Updating from the Pew Internet & American Life Project: http://pewinternet.org/Reports/2009/17-Twitter-and-Status-Updating-Fall-2009.aspx
From the site: "Some 19% of internet users now say they use Twitter or another service to share updates about themselves, or to see updates about others."

I thought this information might be of use to all of our library service planning.