Rub rim of margarita glass with lime; dip in salt or super-fine sugar. Fill glass with ice. In a cocktail shaker filled with ice, squeeze juice from the lime wedge; add cranberry tropical juice, tequila, triple sec and agave nectar. Shake until thoroughly chilled. Strain into prepared glass. Makes 1 serving. For frozen margaritas, sugar rims of 2 margarita glasses as described above. Squeeze lime juice into blender container. Add 5 ounces cranberry tropical juice, 2 ounces tequila, 1 ounce triple sec, 2 teaspoons agave nectar, 3/4 cup frozen pineapple or mango chunks and 2 cups ice cubes. Blend until slushy. Pour into prepared glasses. Makes 2 servings.