In a blender, puree the first five ingredients until smooth. Strain through a fine sieve and fill ice-pop molds or paper cups three-quarters full. Freeze 1 hour.
Remove molds from freezer while the mixture is still slushy. Stir a few cantaloupe balls into each. (Melon balls can be sliced in half if necessary.) If using paper cups, cover with foil and insert sticks. Freeze 3 to 4 hours.