This is rather mind blowing. From Slashfilm:

Jeff Desom built a sort of 3D digital model of the apartment courtyard from Alfred Hitchcock‘s film Rear Window, and then composited all the events seen from the window of Jimmy Stewart‘s apartment into a single shot that covers a couple days and nights. It’s like watching the film play out if you were the person who lived next to or above Stewart’s character, and it is a surprisingly beautiful way to look at the film.

Here is the clip:

You can visit Jeff website for a fuller explanation of his process for the video here.

Thanks to the many people who emailed or tweeted the link to me.