Rule number one of coffee: You need fresh coffee. New Coffees is a dead-simple website and Twitter feed from the New York Times' Michael Young that tells you when the latest coffees arrive at top-notch roasters around the world.
It's easy to see how this concept, Twitter the food messenger, could be expanded further into all kinds of food stuffs: When fresh watermelon arrives at the green market, there's new cheese out of the fromagerie or the latest seasonal microbrews drop into your local beer store. Maybe your fridge could tweet at you when the milk goes bad. [new coffees]