In medium size saucepan over medium high heat, bring water, sugar and Sweet 'N Low® to a boil; boil about 5 minutes. Meanwhile, in cup, sprinkle gelatin over water; let stand 5 minutes to soften gelatin. Stir into syrup mixture. Pour into large bowl and refrigerate 1 hour or until well chilled. In blender or food processor, puree cantaloupe, lemon juice and crystallized and ground ginger; stir into chilled syrup. Pour into aluminum loaf pan. Cover with foil and freeze 2 to 3 hours or until edges begin to freeze and center is slushy. Remove to large bowl, breaking up any chunks with a spoon. With mixer at medium speed, beat to a smooth consistency. Add egg whites and beat again. Return to loaf pan, cover and freeze 4 hours or until almost firm. Beat again and freeze several hours or until firm.