A pulsejet sure sounds like it belongs on a spaceship or something, but it's actually one of the most primitive (or at least simplest) types of jet engines there is. The Nazis used pulsejets on their first generation of cruise missile, the V-1, and now Boeing is toying with the idea of getting them to power a VTOL aircraft.
WWII was a long time ago, and the Nazis did kind of lose, but there is one remaining vintage V-1 Argus pulse jet engine that still works, at the Planes of Fame museum in Chino, CA. Here it is being fired up on video; make sure and turn your subwoofer waaaaay up for this one:
That buzzing that you hear is why the V-1s were called "buzz bombs," and is caused by the pulse part of the pulsejet: the engine isn't operating continuously, but instead it's firing about 43 times a second, producing about 750 pounds of thrust on and off fast enough that it can keep flying. The Nazis liked it because it's reliable, simple, cheap, you can build one in your garage, and it'll run on just about anything.
Boeing likes pulsejets for all the same reasons as the Germans did, which is why they're looking to use them as a vertical take-off and landing system in a new concept aircraft. Boeing's updated pulsejets use no moving parts, relying instead on a pair of cleverly designed tubes that use the pressure from one pulse to compress and ignite the next. And instead of one big pulsejet, Boeing's concept uses a bunch of little modular pulsejets just for vertical take-offs and landings:
The concept featured in the above video would be able to lift between 50 and 60 thousand pounds vertically with a range of over 500 miles. It wouldn't exactly be the stealthiest aircraft we've ever seen, but for a slick and efficient adaptation of what is to the jet aircraft world an ancient technology, this pulsejet idea seems to have a lot going for it.