Imgur.com has a nifty slide show of off-the-cuff moments on the set of famous films. My favorite is below, from Rebel Without a Cause showing James Dean and Natalie Wood talking with director Nicholas Ray. I also like the Angie Dickinson one (what is she wearing & why? haven't seen that one!). The Hitchcock & Hedren photo is too, too classic! Which ones are your favorites?