You cannot plug Kinect directly into an Xbox 360 Elite. The Elite (and all original "Phat" 360s) lacks the dedicated Kinect port.
Kinect works on all 360 models with adapter. Features: voice, gesture, video chat, Kinect Adventures, Dance Central, Child of Eden, etc. No Xbox One Kinect (different connector, USB 3.0).
Get the adapter—it's the only safe way.