I don't often point to comments in other blogs, but Ian Brodie shares some good perspectives on consultants using Twitter (link). It is worth a read if you are a professional consultant and trying to update your perspectives on Twitter usage. I'd agree with a lot of Ian's writeup with two adds for me that Twitter allows me to 1) interact with a wide demographic of people, and 2) experiment with ideas more frequently (albeit more limited) than other social media mechanisms. There is also perceived lower risk given the transitory nature of tweets. Characterizing it from a somewhat different angle, for me Twitter is more about exploration as opposed to exploitation.