2 of 18Image
This is the box the Kinect Sensor comes in. It's a little smaller than I expected, and Microsoft is very careful to call it "Kinect Sensor," rather than just Kinect.
The back of the box shows some very happy people. My initial testing shows that the sensor won't actually work in a room the size depicted on the box. Instead, you need a much larger space.
Here's a zoom-in on the "how much space you need" image from the box back. Six feet won't cut it. In reality, you probably need a space at least about 12 feet by 8 feet, if not more.