Those of you who are regular readers know one of my Google Earth hobbies is to look for aerial or satellite photos which have captured planes in flight. There are actually a number of people at the Google Earth Community who share this hobby, and there is a "database" of placemarks which show all of the planes in flight found to date. The placemark collection is constantly changing because Google updates the imagery database on a regular basis. If you find a plane in flight (or planes), you should check first to see if its already in the database. Here is a network link for the database of all the known planes in flight around the world.