First, it's great to be part of this most excellent Collaboration Soapbox community! As many of my colleagues know, I have helped to promote a cross-IBM web 2.0 initiative over the past 2 years we call Web 2.0 Goes to Work. In doing so, I have gained some great experience in using some of the social software tools such as Twitter to advance market awareness and increase 'drive to' to our web site. The web20work twitter account (http://twitter.com/web20work) has over 600+ followers (and growing by about 4-6/day) and has been an effective tool for promoting a range of IBM activities such as Web 2.0 events and innovative technologies/offers such as associated to Cloud Computing and others that come from our research team. Any company can tap into and gain the same benefits of using a tool such as Twitter.
Need to jump on a call right now but will be checking in regularly to see what others are posting and to share more thoughts/insights.