1. Cut jicama, cucumber, and pineapple into sticks or slices about 2 inches long and 1/2 inch thick. Arrange on a platter. Squeeze lime over vegetables and fruit.
2. In a small bowl, mix cayenne, paprika (or ground dried ancho chile), and salt. Sprinkle half the mixture over vegetables and fruit. Offer lime wedges and remaining chile salt to add to taste.