In addition to a Carl Zeiss 5X zoom lens, 3.5" wide/touchscreen LCD, Sony's Cybershot T200 features a smile sensor that will automagically snag shots when your family and friends are pretending to enjoy your company. In this demonstration, the potential gimmick seems to actually work. Though you'll notice that the sensors have a tough time detecting profiles.
So, if someone was frowning and you flipped the camera upside down, would it still take the picture, or be smart enough not to? Would it realize that the bottom of the face was now the top?
I'm getting one of these cameras just to test this theory, and just because I think it would be hilarious to walk around with and hold down in the middle of a crowded area to snap people's pictures with.