This statement may lack humility but I have argued long and often (without much effect I'm afraid) that NGOs and advocacy groups are more skilled at using social networks than most corporations which have many times the monetary and personnel resources. Penury apparently fosters ingenuity, flexibility, and speed I guess.
Anyway, there is a new book out called Mobilizing Generation 2.0 that according to danah boyd is a "how-to guide to help those who want to mobilize using the web, focusing on how organizers can leverage blogging, social network sites, photo/video sharing, mobile phones, wikis, maps and virtual worlds." boyd herself has an essay in the book about the online world as a form of "public space" (or as I have called it, again immodestly, a new' demos').
I'll take a look, as should any corporate communicator who may face angry citizens armed with participatory technologies. And which company can say it hasn't . . . or won't?