BEAT sweetened condensed milk, lemon juice and peel in small mixer bowl until combined. Fold in whipped topping; pour into crust. Cover; refrigerate for 2 hours or until set. Garnish with lemon peel.
NOTE: For a lower calorie and fat version of this recipe, a 6-oz. prepared reduced-fat graham cracker crust and fat-free frozen whipped topping can be substituted for the shortbread crumb crust and frozen whipped topping.