This is a complex opportunity to which many of us in open data are trying to respond. (Disclaimer: I'm the Evangelist for Data.gov and this answer addresses examples from my work there and at NASA.)
There are two broad kinds of communities to engage in around open data. One is the technical community, like many of you here, of users and consumers of the data, developers, analysts, academics, and researchers who are data- and tech-savvy. A second type of community is represented by citizens and businesses who want to learn from or act upon the information gathered from the data.
In addressing the first community, the responder above is correct in that the best way to have conversations with people is to go where they are congregating. Hence, members of the Project Open Data and Data.gov team helping to initiate this Stack Exchange, and many of those people showing up a networking events around the country and the world to share, listen, and learn from others. We do host forums on the Data.gov site but the effort to lift up those to bring people there for conversation isn't as useful as having broader conversations here.
For the second type of community, we have a focused effort building on a rich history of work in communities of practice. These show up as communities on Data.gov organized around areas such as Energy http://energy.data.gov, Research and Development http://research.data.gov, and Public Safety http://safety.data.gov, and local data as well such as Cities http://cities.data.gov (see the listing of all 18 communities at http://www.data.gov/communities/). The communities on Data.gov are public-facing spaces that present data, information, and subject matter knowledge about a single topic from many agencies in one place. The topics for these communities are chosen based on priorities from the public, agencies based on their mission, or issues of national importance.
The Data.gov team provides services to help each community determine the following:
- Vision: What will the community connection and collaboration look
like in the future?
- Leaders: What core group will help to lead the
- Participants: Who will participate? This could include
application developers, scientists, analysts, consumers or providers
of services, and members of the broader community.
- Outcome: What are the expected outcomes, metrics, and measurements that will show
success? Examples might include challenges around a tough problem
in the field, a set of applications or guidelines that help people
make better decisions in this area, an API or data library, smart
phone apps, and visualizations and mashups. How will this community
work to improve the lives of American citizens?
- Functionality: What
types of activities will be conducted on the site (forums, blogs,
wikis, ranking, rating, challenges, or apps)?
- Content: What
content should be displayed? For example, this could be the conduit
to other resources within or outside of the government.
- Interactivity: What ways will the community interact with the
leaders, with each other, and with the public?
I've found the most effective communities look at the entire open data ecosystem, from getting agencies to release useful and usable data to putting it in the hands of citizens and businesses to make decisions. Active leaders (inside and outside of government), diverse participants, online and offline interaction, integration with existing initiatives and businesses, and focused goals help drive these communities forward.