STIR boiling water into dry gelatin in medium bowl 2 minutes until completely dissolved. Add enough cold water to ice cubes to measure 1-1/4 cups. Stir into gelatin. Refrigerate 1 hour or until thickened (spoon drawn through leaves definite impression).
STIR in apples, celery and bananas. Pour into 3-cup serving bowl.
REFRIGERATE 1 hour or until firm. Garnish as desired. Store leftover gelatin in refrigerator.