Beth Kanter's wiki
Easter Seals has a social networking policy that Beth will blog about soon.
A CEO who is the "face" of the organization on, say, Facebook, doesn't have to actually maintain the the profile... but have a staffer that maintains & briefs the CEO on what comes in from the profile.
How do you measure success, and how to document this?
Don't be obsessed about numbers... qualitative info helps to understand the numbers.