From Xbox Live, here is the Coding4Fun Kinect Turret! It uses the Kinect for Windows SDK and uses a combination of skeleton tracking and depth data to defend your office! The project took only a few hours to build and code up.
Head over to Channel9 to check out the Tech with Tina clip if you missed it on Xbox Live and the Coding4Fun article on how to actually build and code the turret!
Everything used was random parts laying around in my office. I'd recommend swapping out the pan system as what I used was borrowed from the Windows Phone t-shirt cannon we used at Mix. You can get away with chances are normal pan since you don't
need to move around 50 pounds of t-shirt cannon goodness.
Primary hardware used: