I made this last night, and my guys loved it...
1 reduced fat graham cracker crust
1 (4 servings) package sugar-free lime gelatin
1/4 cup boiling water
1 (8 ounce) container fat-free whipped topping
2 (6 ounce) key lime pie yogurt
1. In a large bowl, dissolve gelatin in boiling water.
2. Stir in yogurt with wire whisk.
3. Fold in whipped topping with wooden spoon.
4. Spread in crust.
5. Refrigerate for at least 2 hours.