Render-to-Texture What Camera Sees

Hello. You’re probably familiar with the various mirror shaders out there using render to texture. My question is, is it possible to make a “transparent” one? As in, instead of it calculating the mirrored image, can it just calculate the image that the camera would normally see? So basically, the plane with the rendered texture on it is cloaked, or looks transparent, when it is actually the rendered texture you are seeing.

This would be useful for applying real refraction, instead of cube mapped refraction and other cool stuff. Thanks for any replies. I hope this thread will stay alive for a bit.