In the past, they were called "informal networks": brainy employees, passionate about their work who would get together informally to exchange ideas, debate over the best approaches and methods, and even come up with effective and creative solutions to real challenges.

These groups have actually proliferated in recent years, according to consultants Richard McDermott and Douglas Archibald, authors of the article "Harnessing Your Staff's Informal Networks" in the March issue of Harvard Business Review. Today, however, these networks aren't so informal anymore. Now known as "communities of practice," these groups of subject experts work in a much more structured way, complete with goals, accountability, and oversight. Examples from organizations that use such communities to significant advantage show that in fact today's global, technologically sophisticated business environment, structure and oversight are what make communities work best. And at their best, these communities are like inexpensive mini-consulting groups for the organization, solving problems and gathering valuable research.

Until now, communities were largely been ignored by management because leaders saw them as casual activities that took place on employees' own time. Today communities are not only recognized but considered an integral part of the intellectual machinery at several organizations including the United Nations, pharmaceutical company Pfizer, and heavy-industries specialist Fluor.

Setting up communities of practice takes strategy and thought in order to be effective. To design a group of valuable, lasting communities, senior management must take the first step by defining real issues of organization-wide importance. At the U.N., for instance, communities are designated to address issues such as education, nutrition, and HIV/AIDS prevention in poor countries. Another example is Pfizer, where a network of communities provide important counsel in drug safety.

Communities also need goals and expectations to which they're held accountable. This can mean anything from integrating community members' contributions into the performance review to establishing benchmarks as requirements for promotion.

Governance by senior managers designated as community sponsors are also critical, particularly in facilitating operations and execution of activities. In addition, senior management must be fully committed and engaged.

Communities don't cost much and can have the most impact with just a few conditions. Sponsors and management must set aside specific times for participation. The biggest obstacle to participation after all is lack of time apart from members' actual jobs.

Targeted training for the employee leaders of the communities. Community leaders are most effective when they know how to engage participants, set and reach goals, and measure success.

In today's environment in which technology enables people to engage from anywhere, face-to-face gatherings are still important -- perhaps more so. Meeting other members in person makes it easier to exchange advice and learn from each other's mistakes in a collegial setting.

Finally, IT needs are minimal. Communities don't need much beyond discussion forums, file libraries, and virtual conferencing tools.

Establishing communities with these simple requirements can provide a big payoff, especially in lean times when fewer resources are available for bigger workloads.