For dip, in a blender container or food processor bowl combine ricotta cheese, sugar, lemon or orange peel, and orange juice. Cover and blend or process until smooth. Stir cheese mixture into the yogurt. If desired, cover and chill dip up to 24 hours.
Serve with assorted fresh fruit. Garnish dip with additional finely shredded orange peel, if desired. Makes 4 servings.