1 can (6 oz.) lemonade or limeade, frozen concentrate
1 pt. nonfat frozen vanilla yogurt (or ice cream), softened
1 (8 oz.) pkg. frozen whipped topping ("lite" or regular), thawed
1 ready made graham cracker pie crust

Place concentrate in large mixing bowl and beat about 30 seconds. Gradually spoon in yogurt or ice cream and blend. Fold in whipped topping, whipping until smooth. Freeze, if necessary, until mixture will mound. Spoon into pie crust. Freeze until firm, at least 4 hours. Store any leftover pie in freezer.