Freeze 1 cup of the beverage in ice cube tray with divider in place.
Pour remaining carbonated beverage into small saucepan and sprinkle with gelatin.
Place over low heat, stirring constantly until gelatin dissolves.
Transfer to blender with dry milk and sweetener; blend well and, with blender on, add frozen cubes of carbonated beverage, one or two at a time.
Pour into dessert dishes and serve at once, or refrigerate.