[Porter Novelli CEO Gary Stockman Tweeting (we think) away. Image courtesy BusinessWeek]

BusinessWeek posted a list of 50 CEOs who Twitter today. As one may suspect, many of them come from "hip" little tech companies like Seesmic, Digg and Brightcove.

However, a few PR CEOs also made the list. Porter Novelli CEO Gary Stockman is included, despite having only 160 followers and 37 total updates. Stockman says Twitter allows PN to do "incredible things for our clients, including rapid-response consumer research, direct dialogue with stakeholders, and real-time dissemination of information, which can be especially useful in a crisis."

PerkettPR President Christine Perkett said her favorite Twitter follow is Ann Handley of MarketingProfs and that she uses the service partially because: "We've had the advantage of receiving 'first mover information' -benefiting both our agency and our clients-by connecting with reporters who often tweet about what their stories are going to be before anyone else knows about them..."