I think it is really important to be part of the online world, through blogs, discussions and groups not only to share our experience but also for networking, resource sharing, collobaration and professional development. Below are some online communities that I have found exteremly useful for collobarative knowledge building.
http://www.edweb.net/
It offers free professional learning communities and webinars. You can be part of current communities or create your own one and invite your colleagues to join in.
http://www.wise-qatar.org/wise-community
You can communicate with educators, innovators from many countries who influence education. You can create your own group and join many fascinating ones and become a part of an exciting community.
http://www.tigweb.org/
TIG Initiatives provides you a flexible and powerful online space to share what you’re working on with the world. It encourages collaboration with other motivated individuals and organizations. You can change your own design, add your own features and content, and even link it with social networking tools like Facebook and Twitter. Showcase and connect your ideas to a global community!
http://www.linkedin.com/home
Linkedin not only allows you to connect with your colleagues, you can also join many linekdin groups in your interest area and create your own groups.
https://twitter.com/
You can find what’s happening with the people and organisations, but also share your activities with them. I love it because it is the fastest way of communicating at the moment!!!
http://twbglobal.org/
Teachers without borders connects teachers to information and each other so that they can create lcoal change on a global scale.