Making communities of practice fly. Diane Le Moult has written an excellent summary on how to make CoPs work. This is written from her direct experience, and highlights a number of very useful guidelines: 10 fundamental questions you need to ask before starting a CoP: [...]

[...] Finally, we identified 10 classic pitfalls you have to be aware of:

1. Ignore moods and demands of members: People participate primarily for themselves, not for you or an executive demanding certain results.
   Therefore always have an open ear for the members, motivate them to shape their community.
2. Not enough content: You have to reach a critical mass which differs. If there is not enough interesting content, people will work less in the community, contribute less. That´s a real vicious circle!
3. Too strict or too loose: People need leadership but don´t want to be cramped. Due to the voluntary character of communities, finding the right way is a challenging task.
4. No scope: People need room for innovation and creation but also noticeable landmarks for orientation.
5. No aims: Communicate your estimated aims and outputs and be open to discuss.
6. Only technical platform: „First invest in travel and in beer, then in information technology“ (from EFQM Benchmark KM).
7. No Admin response: Assure that people are heard when they have problems and get useful answers.
8. No support (help and training): Effectiveness needs constant support and trainings - especially for the key members.
9. Only extrinsic motivation: It is impossible to achieve quality results when the members don´t have a natural interest and need for these.
10. Bad moderation: Even the best experts need qualified moderation and facilitation.

... [Column Two via thomas n. burg | randgänge]

Very good points, though I'd say that properly taking them into consideration probably requires considerable experience.

(Ever notice how enumerations and bullet lists seem so good at traveling from one aggregator to the next? Something to remember.)