G. Mick Smith, PhD, Senior Educational Technology Executive: https://www.linkedin.com/in/gmicksmith/
Diigo is a powerful research tool and knowledge-sharing community.
Free lesson plans and educational resources. For example, in AP Economics, you may be studying elasticity and you can find a number of resources on the topic.
Google offers a number of services that classes, educators, and work environments are using.
Archbishop Wood High School faculty uses a wiki as a result of the Archdiocese of Philadelphia Cohort.