I got this from Linda's recipe site and wow is it good.
I used davinci raspberry syrup and for the water I used Nestle Raspberry Splash flavored water.

http://users3.ev1.net/~fontlady/raspberry_dream.html

RASPBERRY DREAM
2 small packages diet raspberry jello
12 ounce bag frozen raspberries, thaw and reserve juice
1/4 cup granular Splenda, 1/4 cup raspberry sugar free syrup or equivalent liquid Splenda
6 ounce carton low carb vanilla yogurt
1 cup heavy cream, whipped


Sweeten berry liquid with Splenda or raspberry sugar free syrup. Add water or syrup to berry juice to make 1 cup liquid; bring to a boil on stove or in microwave. Dissolve jello in berry liquid; stir in 1 cup cold water. Whisk in yogurt until well blended. Chill until partially set, about 40 minutes; fold in berries and whipped cream until no white streaks remain. Pour into a large serving bowl and chill several hours until set.

Makes about 12 servings

With granular Splenda:
Per Serving: 101 Calories; 7g Fat; 3g Protein; 6g Carbohydrate; 2g Dietary Fiber; 4g Net Carbs
With liquid Splenda or sugar free syrup:
Per Serving: 99 Calories; 7g Fat; 3g Protein; 5g Carbohydrate; 2g Dietary Fiber; 3g Net Carbs