Check out this terrific article by Jennifer Young, a former intern with the American Society for Nephrology, on how this society entered into the world of social media and transformed itself in the process. As she says, as ASN began looking to expand its audience and its mission, it realized "a shift in focus really required a shift in media."
She outlines step-by-step how ASN worked its way into social media, and some interesting lessons learned along they way. One thing that struck me is how the communications team was intent on collecting data, both on what other groups were doing and in collecting statistics on ASN's own efforts.
Thanks to SocialFish for the pointer!