David Weinberger is a technologist and commentator, probably best known as co-author of the Cluetrain Manifesto (originally a website, and eventually a book). Weinberger's work focuses on how the internet is changing human relationships, communication, and society. A philosopher by training, he holds a Ph. D. from the University of Toronto, and currently serves as a fellow at the Berkman Center for Internet and Society at Harvard Law School. He is also an avid blogger. He was an advisor to Howard Dean's 2004 presidential campaign.