Yep, I had in mind filiming it from the side. Sort of a walk off the edge of a split screen effect.
It's going to be tough to do a head on version I suspect. My first thoughts are that it would be a serious compositing exercise, something along the lines of the following.
Have an empty mirrot frame (or open doorway maybe?). Shoot you )(from behind) walking into it.
No go through the door and film you walking through it from the front. remember to make it exactly the same as the first one. This will be the mirror shot once it's reversed.
Also shoot some footage, from the front of the empty doorway.
Now just (
) composit the three bits of footage and a bit of touching up frame by frame (maybe) until you are happy.
Like I said. I don't think it would be easy.
let us all know how it goes though
