In a blender, combine guava nectar, pineapple juice, and fresh pineapple chunks. Cover and blend until smooth. Divide chopped or sliced fruit among 12 frozen treat molds or 4- to 6-ounce paper cups. Pour blended mixture over the fruit.
Cover each cup with Reynolds Wrap(R) Aluminum Foil; make a small hole in the aluminum foil with a knife and insert a wooden stick into each cup through the hole. Freeze about 4 hours or until firm. Remove foil and cup to serve.