It's an interesting idea.

Especially with the Fcamera software.

So basically you would:
Take 1st photo.
"slide" the n900 to the side (left or right?) - an on-screen guide will help you.
Take 2nd photo.
Some kind of "depth" measurement between 2 photos.
Render the final image from photo 1 & photo 2

Is that right?

Sounds cool!