1. Sprinkle gelatin over 1/4 cup of the ice water in small saucepan; let stand for 5 minutes to soften. Place over very low heat just until gelatin is dissolved; cool.
2. Meanwhile, sprinkle dry milk powder over remaining 1 cup water in medium bowl; chill for 5 minutes in refrigerator.
3. Using electric mixer at high speed, beat dry milk mixture until soft peaks form. Gradually beat in cooled gelatin, yogurt, lemon juice and lemon rind.
4. Use in recipes specifying Low-Calorie Whipped Topping or to swirl over fruit salads and other low-calorie desserts.