Click here for a photo gallery of our favorite bombshell fembots from television and film.

Fembots were a pop-culture staple long before Austin Powers battled them-witness the popularity of The Bionic Woman, The Stepford Wives and Blade Runner. But what is it about curvaceous cyborgs that stirs the imagination?

For years, the U.S. military has wanted a plane that could loiter just outside enemy territory for more than a dozen hours and, on command, hurtle toward a target faster than the speed of sound. And then level it. But aircraft that excel at subsonic flight are inefficient at Mach speeds, and vice versa. The answer is Switchblade, an unmanned, shape-changing plane concept under development by Northrop Grumman.