Top spot from my US colleague Stephen Trimble here. On the face of it, the photo - very nice though it is - shows a Lockheed Martin F-22 flying over the Nevada desert on Exercise Red Flag. So much, so what. But as Trimble points out, in the background you can clearly see the runway at Groom Lake, also known as the US Air Force's secretive Area 51 testing area in the heart of its Nevada test range. The picture is on the Defense Video & Imagery Distribution System website, should you wish to see it in its original form. USAF doesn't normally release pics of Area 51, as it doesn't exist.