As in a radar pattern created by a fractal flash light.
The wallpaper version is available at the preceding link.
Today's Gratitude Item: Usability that is so bad, it's good. One of the small programs that I'll be using for my Computer Science class features a button with a "Jolly Roger" symbol. Said button is actually the delete key. I'm guessing they could not find a suitable trash icon anywhere. This breaks two of our usability rules (ie: the rules which say systems should stick to known conventions and, where possible match the real world). It's normally quite difficult to find examples of these rules being broken so this was quite a 'find'.