Is Twitter now an enterprise productivity tool?

I would have to concur with Marshall Kirkpatrick. I also now use Twitter as a working tool, not just for ‘status upates’ (which I don’t really do any more unless I can say something vaguely informative or funny). I use it to interrogate and interact with my work and social contacts. It’s now one big ongoing conversation which can help me in my work, and especially in writing stories. I