I get calls and emails almost every day from folks who want to know: "How do I start a Facebook group?" My response, invariably, is: "WHY do you want a Facebook group?"

That's the topic we're covering this week in We Are Media: Social Networks (and Widgets) for Community Building, Taking Action, and/or Fundraising. Why are social networks important to our causes? Under what conditions? And what kinds of investments do you need to make to get the most out of them?