We are all obsessing about how we can blurt out anything about everything in increasingly small and public chunks. We can follow Opra, Ashton Kutcher and and now the White House on Twitter and have thousands of friends on Facebook. While, all this is fun and useful, it's such a small part of how we actually share and communicate.
Personal sharing and personal communication whether with family, close friends or co-workers is a critical part of my everyday life. Plum Groups has become the main way I have private, contextual, ongoing, social exchanges with the people in my real life while Twitter is where I get bombarded with the fun, funny, interesting and trivial status updates of people I've deemed worth paying attention to.