In small saucepan, sprinkle gelatin over cold water; let stand 1 minutes to soften. Warm over low heat to dissolve. Combine in blender softened gelatin, cream cheese, yogurt, Sugar. lemon peel, lemon juice and vanilla. Blend until smooth, scraping sides as needed. Add ice cubes; blend until smooth. Divide grapes between six (6 oz) custard cups or individual dessert dishes. Pour Cheese mixture over each, dividing equally. Chill until set. Garnish with additional grated lemon peel and grapes, if desired. Calories: 97 fat: 2 g sodium: 141 mg cholesterol: 6 mg