I was at an annual scientific conference this week, and it was all about communication, and we were told if we don't tweet, we should start! As others have mentioned here, when used appropriately, it can be very useful and informative.
I have an account, only because I fill it with running stuff mainly, and have contacts who are running related which provides helpful links. This separate twitter account is so that I don't bore all my non-running FB friends with my running!
That's precisely the problem, though, as I see it, being told that if you don't tweet you should start. "Communication" for the sake of it. Lots of people with nothing to say wasting time filling up cyberspace with crap for other people to waste time reading.
It may be as much as 50% useful but the other 50% is utter guff.
Stop f*cking tweeting and MAKE something - knit a jumper, cook a casserole, go for a run, seriously there are much better things people could be doing with their time.
Rant over 