I shot a 4 min interview at 720p and rendered it out as a beautiful .mov file. But the client now needs it in 640x480 (for an online distributor). How in the world do I get this into a "letterbox" form and get it to 4:3? I have iMovie, AE, FCP (though I don't know how to use FCP very well), and Flip4Mac as basic tools. Any help would be greatly appreciated.