Okay, so I've heard of some pretty weird diets, but this one is impressively odd. Hans found this at the Creating Passionate Users blog, which is done by a geek who teaches brain hacking for programming. It's called the Shangri-La Diet, for reasons completely unknown to me. It was conceived by a guy named Seth Roberts, who is an associate professor of psychology at the University of California at Berkeley.
While it may be the strangest diet, it also appears to be the easiest and least dangerous diet ever. There appears to be only one rule: find two solid hours each day where you don't eat anything. During that time, you ingest a small amount of sugar water or a small amount of pure olive oil. That's it. I'm sure the book (or perhaps this nice little white-paper) explains this in detail, but I guess that's what it comes down to. Very interesting.