Seth Godin, marketing guru/Mensa
Matt Blumberg, Übermensch founder of Return Path and author of Startup CEO: A Field Guide to Scaling Up Your Business, + Website
Gifford Pinchot, President and a founder of the Bainbridge Graduate Institute, a leader in the movement to bring sustainability and economic justice into the business school curriculum and thereby into business practice
Passion & Purpose, blog created to promote book of the same title
Devin Thorpe, Forbes social entrepreneurship blogger & author
Pascal Finette, this is really good, trust me
Causecast Blog, from the corporate philanthropy and volunteering platform