I know I'm preaching to the converted, but here is another article supporting the use of social networking for learning. You may or may not choose to look at Rypple, but the concepts can be used
This is a practical article describing a method to encourage teachers to USE technology. It found that most teachers don't find tech training helpful as it focusses on HOW to use technology not how to INTEGRATE it into teaching and learning.
Future Tense is essential listening for those interested in exploring the social, cultural, political and economic fault lines arising from rapid change. The weekly half-hour program/podcast takes a critical look at new technologies, new approaches and new ways of thinking. From politics to media to environmental sustainability, nothing is outside its brief. Future Tense explores the issues and provides critical analysis, offering an insight into how our world is changing and how we in turn are learning to adapt., ABC Radio National, ABC, Australian Broadcasting Corporation