Electromagnetic Propulsion using Microwaves

Imagine hovering vehicles that do not have wings. I just bumped across an posting on Slashdot "Thrust from Microwaves - The Relativity Drive" that mentions this. Roger Shawyer calls it emdrive and NASA and China are serioulsy looking into this for a future space propulsion system. The orignal NewScientist article "Relativity drive: The end of wings and wheels?" describes it in more detail and has an interesting conceptual picture of what may be possible.