If you're in advertising, technology, R&D, planning a startup of your own, or are just a dreamy futurist, I recommend going through PSFK's "The Future of Real-Time." It defines relevant topics like human sensor networks, personal census, data democracy, mobile communities and context cartography. Each is illustrated with a number of concrete and current examples.
Perhaps most importantly, it will take your thinking about real-time tech out of "Twitter! Foursquare!" stasis, which I imagine will be a welcome relief.
