In a 2-cup measure stir sugar into warm water until dissolved. In a blender container or food processor bowl combine half of the sugar mixture, half of the fruit, and half of the lemon juice. Cover and blend or process until smooth. Remove. Repeat.
Freeze in a 2-quart ice cream freezer according to manufacturer's directions. (Or, pour into a 9x5x3-inch loaf pan. Cover; freeze for 4 to 5 hours or until almost firm. Break into chunks. Transfer to a chilled large mixer bowl. Beat with an electric mixer on medium speed about 2 minutes or until fluffy. Return to cold pan. Cover; freeze 6 hours or until firm. Makes 1 quart (8 servings).