I do the knock on wood often and the salt thing sometimes. Ive never heard of some of the others mentioned. My great-grandmother was very superstitious and my mother told me some of the things that used to freak her out: opening an umbrella inside the house, putting a hat on a bed, stepping on cracks in the sidewalk. Some of the other things are more like omens: if your nose itches, youre going to kiss a fool; if your palm itches, youre going to spend a lot of money; if someone drops an eating utensil, that means company is coming (knife = man, spoon = woman, fork = fool). (I often yell out, companys coming, when someone drops a utensil.) Years ago, someone gave me a rabbit's foot, and I often take it with me - in my purse, tote bag, or suitcase.