Twitter : we all need to be in the loop

James Harkin ( author of Cyburbia: The Dangerous Idea That's Changing How We Live and Who We Are) writes an interesting article in today's Times.
He says :
"Twitter's coming of age, however, is generally dated to the Mumbai terror attacks at the end of November, when minute-by-minute updates of the unfolding chaos zipped around the world by eye-witnesses armed with Twitter on their laptops and mobile phones."
He's concerned that all this tweeting activity, after the initial boost in productivity and creativity, where we are learning to do many things at once, is affecting our brains and could slow us down in the longer run. Are we just tweeting because it is the thing to do?
There's also a little starter's guide to Twitter.