Some of the topics covered are: ESP, Dianetics, dowsing, Atlantis, and various food fads. Some things I have met, such as training the eyes so that you can see without glasses. Gardner is actualy fairly sympathetic to the attempts to test for ESP.
I really wish Prince Charles would read this book, but he is a lost cause to rationality. In the past I have taken a relaxed attitude to strange beliefs. People can believe what they want. However people are making a lot of money out of selling pills and potions.
I do "admire" some of the stranger beleifs, such as the Earth is flat or hollow.