It's not every day that Microsoft shows off its own technology being used for the forces of evil, but it did just that during company head Steve Ballmer's keynote at Mobile World Congress. Engadget was on hand to witness Kinect Adventures' Rally Ball minigame being controlled not just by a Kinect, but also two Windows Phone 7 devices controlling the flow of rubber balls being distributed. It's all fun and games until the gentleman playing is overtaken by a monstrous flood of rubber balls.

Microsoft notes that the demonstration was strictly a "tech demo," but it certainly hints at the possible future of Windows Phone/Xbox integration. It also opens the pandora's box-like door to Kinect/WP7/Surface crossovers, finally. Get a look at synergy in action just after the break.