Enjoy this frozen fruit dessert without a lot of bother or even an ice-cream maker. All you need are a few fresh melons and a food processor. First, cube a melon and freeze it in a food-storage bag. When you're ready to make sorbet, place frozen melon in the food processor, and puree. You may need to add water to smooth. Add sugar to taste, and puree again. Serve immediately, or store in the freezer in an airtight container up to two weeks.