Heard about this a few days ago : http://www.newscientist.com/channel/fundamentals/mg19125681.400-relativity-drive-the-end-of-wings-and-wheels.html If it actually works, this is, well, revolutionary to say the least. I'm highly doubtful, but a lot hopeful. Anyhoo, New Scientist isn't exactly known for their reliability to get things right, so that dampens things a lot. I'd take it a lot more seriously if it were in say Scientific American. All this aside, does anybody know if this could actually work? The full article explains how it should have a net thrust in one direction without violating known physics, but I'm not knowledgable in this area to know if they actually did their homework right (again, not a whole lot of confidence in New Scientist).