One hoary truth of computing technology is that most of the pressing problems today have solutions discovered or developed, at least in part, twenty years ago. (This nicely avoids the patent problem.)
Google’s announcement of the OpenSocial API brought up yet again the persistent problem of walled gardens on the Internet, as myriad social networking sites spring up, offer to invite all of your friends if you divulge your address books, and then slowly wither as you realize that visiting half-a-dozen sites every day to read messages from your fragmented social groups is busy work.