In medium bowl, beat egg whites, salt and cream of tartar with electric mixer on high speed just until stiff peaks form. In 2-quart saucepan, stir sugar and water until well mixed. Cover and heat to rolling boil over medium heat. Uncover and boil 4 to 8 minutes, without stirring, to 242°F-248°F on candy thermometer. Pour hot syrup very slowly in thin stream into egg whites, beating constantly on low speed. Add vanilla, orange peel and orange juice. Beat on high speed 7 to10 minutes or until stiff peaks form and side of bowl is cool to the touch. Frost cupcakes. Garnish with orange peel. Store in refrigerator.