We're becoming attached to the term "purposeful communities" to describe the target participants of storycapture: groups of people who have a common agenda and are willing to work together to achieve it.  It turns out the phrase has been used fairly extensively by a group that does leadership training in the educational community.

In "School Leadership That Works", Marzano, Waters and McNulty define a purposeful community as "one with the collective efficacy ... to use assets to accomplish outcomes that matter to all community members through agreed-upon processes." 

http://bit.ly/4erJ8U

They use a phrase: "collective efficacy" which seems very resonant.  We might talk about "collective storytelling" to describe the collaboration we imagine around capturing a community's narratives.

We also found a study that used the term in reference to knowledge management:

Creating and sustaining successful knowledge management in purposeful communities: 

http://bit.ly/1djLOT

And a recent online unconference that explored the concept in the context of community building:

Purposeful Communities / Online Community Unconference 2009

http://bit.ly/1DD6za

The value we see in the concept for storycapture is that the "purpose" expresses the (sometimes potential) willingness of the members of the community to collaborate on storytelling, defining the themes and the process around shared agendas, and (again potentially) accepting a common editorial point of view in order to better achieve that agenda.