The Second Conference on Online Deliberation: Design, Research, and Practice (OD2005/DIAC-2005) was held at Stanford University May 20-22, 2005. From that event there is now a book, Online Deliberation: Design, Research, and Practice, edited by Todd Davies and Seeta Peña Gangadharan (CSLI Publications, November 2009). All content in the book is licensed under a Creative Commons Attribution-Share Alike 3.0 Unported License.
I will call out a few of the many interesting chapters, one of which I contributed to:
Chapter 5: Friends, Foes, and Fringe: Norms and Structure in Political Discussion Networks (John Kelly, Danyel Fisher, and Marc Smith, pp. 83-93)
And two from colleagues who report on tools for facilitating political debate and decision making:
Chapter 6: Searching the Net for Differences of Opinion (Warren Sack, John Kelly, and Michael Dale, pp. 95-104)
Chapter 26: Online Civic Deliberation with E-Liberate (Douglas Schuler, pp. 293-302)
The book is a great guide to the many ways computer-mediated interaction technologies are being used to build consensus or tear it apart!