Just came across this AirportMonitor website that let's you view - at selected US airports - air traffic around the airport. This is quite amazing to see. Not sure how realtime it is but it looks pretty cool at least. Now what do you need that for? Well don't ask that sort of question. I am sure it has value even if it is only the pleasure in knowing that it is not only car traffic but also air traffic we can look at on the web.