Recently, I stumbled across a website I found hilarious and thought some Serious Eaters might as well. It's basically a database of EVERY fad diet (and a few non-fad diets) that have ever existed.

My favorite is the "3 Day Diet," which I remember was passed around my mom's office (on a Xerox copy) when I was a preteen. It's a "magic" 3-day diet that is supposed to produce weight loss if you follow it exactly. One of the meals is

"2 beef franks or hot dogs
1/2 cup carrots
1 banana
1 cup broccoli or cabbage
1/2 cup vanilla ice cream
Black coffee or tea (Sweet & Low or Equal) or water"

http://www.everydiet.org/diet/3-day-diet

Another fad diet I hadn't even heard of is the 'Bread for Life' diet:

"The foundation of the diet is bread; up to 12 slices of bread a day...this must be ‘light’ bread which contains 35-45 calories per slice. Heavier breads and those containing nuts and raisins may have up to 90 calories. These are not forbidden but not recommended for everyday use - and allowed as long as daily bread calorie quota maintained."

http://www.everydiet.org/diet/bread-for-life

My favorite is the pocket diet, which means you have to eat a pita for every meal, and only what can be crammed into a pita.

Anyway, just for laughs. I couldn't believe how long the list was, and how different the diets were!