PictureWindow

Allows the user (outside of HMD) to view into the virtual world by turning the display into a window.

To Use

Drop the unityPackage into a project that is using SteamVR
Add the PictureWindow and VirtualWindow prefabs on [CameraRig], then the PictureWindowUI in the scene, and assign the necessary references in the inspector

More complete instructions available here

Code released under the MIT License.