FlightAware - The future of flight tracking...

Wow. One of the coolest new web apps I have seen in a while. Flight tracking, the way it should be. Looks like they use a combination of ACARS data, FAA-published IFR flight plans, and published airline data to show where all the planes in the air are. Way cool. And be sure to check out the animated day-in-the-life of North American airspace. Awesome!