The Nordstrom flagship store in Seattle has put Kinect in their windows. You can walk by the store and draw on one window using just the motion of your hands.
"Our brilliant Interactive Development, Visual Merchandising and Operations Teams put their heads together and brought light writing with light to life. With the help of Kinect's infrared technology and their technical genius, our teams created a seamlessly interactive display that anyone can "paint" on with using just the motion of their hands in front of the glass," stated Nordstrom.
In the video below, you will notice Kinect's hidden in a fixture below a Dolce and Gabbana handbag: