BuddyPress.org

There are WP plugins that will auto-create a WordPress post from each item in an RSS feed as it happens (well, cron schedule notwithstanding, I guess, or something like that). I kind of hate Facebook, so I’m not sure, but are there RSS streams generated by the appropriate activity there?

Or, come to think of it, if there were an RSS stream from Facebook, you could just use Andy’s External Group Blogs plugin and pull the RSS items into an activity stream for a group, as well.