Boil 1/4 cup of water in microwave and mix with gelatin in small bowl. It will be very thick, and still gritty. In large bowl, add gelatin to yogurt, mixing well. Fold whipped topping into this until well blended. Pour into graham cracker crust, and place in refrigerator for at least 2 hours; longer is better. Remove from refrigerator and serve immediately. Refrigerate any leftovers.
(This recipe can be made with any flavors, choosing gelatin and yogurt flavors that compliment each other.)