Many thanks for sharing your thoughts on Communities of Practice and their role in bridging project teams and networks. Also for my understanding the CoPs are bridging this gap.

I'd like to add two things: their role for common language and understanding, and for the sustainable cultivation of capabilities.

+ Common language and mental models are prerequisites for effectively sharing knowledge and collaborating on complex matters. They facilitate congruent understanding and effective communication.

Common language and mental models can grow from continual dialogue and learning in teams, during intense collaboration on joint endeavors. Both are strongly related to communities of practice since there conversation on complex matters can take place. Why? Communities of practice cultivate disciplines, related expertise, practical skills -- and thus related language. Your statement "You know you are in a community of practice when it changes your practice" reflects this aspect.

+ Communities of practice can also play an important role for quality and state-of-the-art in a discipline.

They represent a resilient, fluid "body of collective knowledge, skills and expertise" able to maintain the good things, and to take up, validate, refine and disseminate new ideas. Quite similar to the guilds of artisans and craftsmen they care for education and quality of the work delivered through defining, adapting to constant change, and disseminating the criteria for good work and related practice.

In a company, a CoP might even be appointed as the trusted technical authority for a certain topic area. If a company (consciously or unconsciously) relies on individual experts ("the guru approach") scattered across the organization, they may face the problem of critical mass or of islands with different cultures, both making international business more difficult than necessary.

I hope these aspects enrich the discussion!