Render GUI as texture in 3D scene?

Is it possible to render the GUI Layer as a Texture, mapped to a 3D plane? I figure capturing click coordinates might be tricky. But, is this doable?

Basically, I want to have unique GUIs on multiple surfaces for a stereoscopic 360 degree interface.

Try making use of Unity 3d - world space Canvas system.

http://docs.unity3d.com/Manual/UICanvas.html