PREPARE jelly powder according to 30 Minute Set Method on package. Set aside 2/3 cup of the slightly thickened jelly. Stir melon balls or cut up fruit into remaining jelly; spoon into 4 dessert dishes.

BEAT reserved jelly with electric mixer until fluffy and double in volume. Spoon over fruited layer in dishes.

CHILL until set, about 30 minutes.