Have you ever watched a plane fly overhead and wondered where it was going? Wolfram Alpha has launched a flight-tracking application that lets you find out. As we head into the most wonderful time of the year for air travel, here's an app that could pinpoint where your delayed plane is. How does it work? In the search box of the Wolfram Alpha app ($2.99 on iTunes and Android), type in “flights overhead" and it will return a list of flights (including the types of aircraft) close to you as well as giving their altitude, angle and slant distance -- along with a sky map that shows the planes' position in relation to the sun and moon. It works using near real-time data (there is a five-minute delay) that is provided by the Federal Aviation Administration. For now, the “flights overhead” feature only sources data from the FAA, so only flights in the U.S. can be shown. But if you live further afield, you can still try it out -- just type a U.S.-based location into the search box, like “flights overhead Central Park New York.” (If you want to find out what plane flew over your house five hours ago, just add the time to the search query.) While there may not be many practical applications for this, it's still plenty of fun for kids or those with more than a passing interest in aviation. Or if you're stuck at an airport...