1 box (0.3 oz.) sugar-free lime gelatin
1/4 c. boiling water
2 containers (8 oz. each) key lime pie flavor, light fat free yogurt
1 container (8 oz.) thawed fat free Cool Whip
1 prepared 9 inch reduced fat graham cracker pie crust

In a large heat resistant bowl, dissolve gelatin in boiling water. With wire whisk, stir in yogurt; with wooden spoon, fold in whipped topping. Transfer mixture to prepared crust; refrigerate overnight or at least 2 hours.