Collaborating involves connecting through online networks. This is a very comprehensive list of networks on social networking and professional networking sites.
"Intel Teach helps K-12 teachers of all subjects learn to engage students with digital learning, including digital content, Web 2.0, social networking, and online tools and resources. Intel Teach professional development empowers teachers to integrate technology effectively into their existing curriculum, focusing on their students' problem solving, critical thinking, and collaboration, which are precisely the skills required in the high tech, networked society in which we live."
Professional Development Network is designed to help teachers, school districts and organizations meet their needs for professional development and best practice instruction.