I think this is a good idea (and better than trying to get all Free Content/Open Knowledge/etc. people to badge themselves as somehow part of our Wikimedia Movement, which though (hopefully!) welcoming and inclusive is not as wide as the whole topic.
I'd note that there is of course the excellent Open Knowledge Definition[0], penned in part by our very own Erik Möller, which gave rise to the Open Knowledge Foundation[1]. Perhaps working with them on this might be a good move?
[0] - opendefinition.org [1] - okfn.org
J.
James D. Forrester jdforrester@wikimedia.org | jdforrester@gmail.com [[Wikipedia:User:Jdforrester|James F.]]
I knew there had to be something like that already. It seems like it would be difficult to adapt an existing organization to the role of a coalition, although if they were willing I think there is certainly room for it and abundant opportunity.