In followup to my previous ranting about 3-D movies looking like ViewMasters. Roger's Ebert's blog has a letter from an Oscar-winning film editor about why 3-D won't work. The argument boils down to parallax vs. focus. In 3-D movies our eyes have to aim near of far depending on the action, but all the while focusing on the screen at a fixed distance. Our brains don't work like that.