http://research.microsoft.com/en-us/um/redmond/groups/cue/soundwave/

Microsoft are using the doppler effect to detect gestures for Kinect-ish gesture control in something called Soundwave. The examples they use in the video look kind of awkward but unlike Kinect this is easier to build into pc's and laptops (maybe even phones) since it uses existing microphone and speaker hardware. Also it apparently isn't thrown off by ambient noise so it should be more portable than Kinect as well.

Also: