Instant messaging is great in the office. You can sit there with an IM tool open on your PC and keep an eye on the chat. And I have sat in an office with a silent team all “working together” and using IM to discuss ideas rather than turn to the person next to them and talk. As in talk loud enough that the other people in the team – also in the office – could hear, absorb and if relevant, engage in the conversation. Personally, I thought it was kind of silly, as for most people it is quicker to say something than to type it, but I have to say it worked really well for them.
Then I heard about a company a few years ago at which the CTO insisted that everyone in his department must always be connected to Skype IM. And that became the predominant means of management – management by instant message. Possibly it was overkill – he could have just opted for Twitter and tweeted his orders. He probably does now.