Engineers, by nature, have an insatiable need to learn. Regardless of specialty, engineers are often most comfortable in an environment that includes like-minded individuals who aren't afraid to push the limits to achieve something new or original. These groups are communities of practice -- informal associations of people who, over time, share information about a practical activity. Whether they realize it or not, modern engineers can trace the lineage of their training to artisans and craftsmen of the past. Communities of practice exist in nearly every organization, whether or not they are formally recognized. Paradoxically, when an organization tries to direct their activities, it runs the risk of reducing their usefulness. Facilitating the effectiveness of communities of practice may be as simple as laying off the gas, so to speak, on the work output expected of engineers. Management must learn to stand back and give communities of practice the organizational space necessary to be most effective.