Flying saucers are generally associated with UFOs, with that "U" in there standing for "unidentified." But the saucer shape isn't just limited to aliens from outer space: there are a fair number of entirely identified terrestrial aircraft that utilize a more or less circular and saucery design.
We've got a list of ten flying saucers for you, each of which made it far enough out of someone's imagination that at the very least a proof of concept was constructed. No blurry pictures that may or may-not-be-streetlights here: these are all real designs that actually existed.
Check out the slideshow below to see the saucers.