Bring sugar and water to a simmer and cook just until sugar dissolves. Chill completely. Stir guava or passion fruit nectar, mango nectar and lime juice into sugar syrup. Puree diced pineapple and diced papaya and add to juice mixture. Pour into plastic container, cover and freeze for 3-5 hours. Stir once or twice. Spoon into cocktail glasses and garnish with pineapple and mint.
Use the same recipe as above but pour into Popsicle molds or use plastic cups and cover tightly with plastic wrap. Make a small slit in the center of plastic and insert stick. Freeze until firm, about 6 hours. To remove from molds, run under cool water.