edited out repeat information: woops there's a link right to this info LOL. There's a few different places to find info on this, that site summed up what i was talkin about tho. Says its about 2x the size i thought, i dunno how acurate those artist's conceptions are, i've seena few different styles. Probably the main problem with that artist's conception is the way the thrusters look, they would probably shift more toward the corners to provide more directional thrust, instead of just lifting thrust.
There's also some other types of UFO-like craft that are supposedly experimented with by the government and now private companies like laser-propelled craft, that probably look more like a conventional alien flying saucer (maybe more bell-like).
http://science.howstuffworks.com/light-propulsion.htm
Here's a company developing some, and they even have a video of them working. This goes a hell of a long way in debunking a ton of UFO sightings.
http://www.lightcrafttechnologies.com/
