Kinda cool (and kinda scary); check the post link below for more details and examples
At one time or another, we’ve all looked at a jet flying high overhead and thought “I wonder where they’re headed?” Actually answering that question probably seemed impossible before—but if you’re a user in the United States, Wolfram|Alpha can now help you answer that question and many more interesting queries about commercial and other flights.
Try the simple query “flights overhead” and you’ll get information on aircraft that should be visible to you, assuming a clear sky and unobstructed view. If you’re on a location-aware mobile device, the results should be based on your precise latitude and longitude—otherwise, Wolfram|Alpha will use the best available location information from your browser. Also note that hovering over an individual plane in the sky map will produce a tooltip with the airline and flight number