One of my favorite Hitchcock films is a lesser known film called Rope. Rope is filmed in real time about a murder done by some young guys who do it just for the experience of performing the murder. Hitchcock was experimenting with ten minute long takes that he believed would save a lot of money. Ultimately, it ended up having the opposite effect because whenever they made a mistake, they had to do the entire ten minutes over again. Not only was this expensive, but it frustrated the actors who had nailed their scenes several times but had to do them over and over again ... all ten minutes not just a few seconds like they usually do. But this technique did give the film a much different quality than a lot of his films with the long scenes and I don't think they ever leave the one room that the film starts in with the murder since it was based on a play.
Rope was also the first time that Hitchcock worked with Jimmy Stewart. Stewart was so frustrated with the filming process that he vowed to never work with Hitchcock again. Obvisiously he changed his mind and starred in the classics Rear Window and Vertigo (which turned 50 this week). A lot of actors including Montgomery Clift and Cary Grant turned down offers to appear in Rope due to the homo-erotic imagery throughout the film. They were still in the closet and didn't want this to give anyone any ideas.