This document discusses using online communities and social networking for professional development and enhancing teaching. It provides examples of how communities can be used for collaborative projects, emotional support, and sharing best practices. However, simply creating a social platform is not enough - communities need measurable goals, engaging activities, collaboration and sharing of results, and institutional support to be successful. Factors like active participation versus passive engagement affect the impact on student performance. Designing instructional sequences and the tools available also influence how students utilize personal learning networks.