Great ambient audio

Air traffic control communications live (except for net latency). Right now listening to rush-hour traffic from SFO Tower, which is two mountains away and hence impossible to hear from the shallow gulch where I sit. But my favorite feed is Schiphol airport in the Netherlands, one of the crossroads of globalization, where English (always; it's the international standard for air traffic control) is spoken in many accents, and planes converge from and radiate out to all the world.