1 graham cracker crust
1 (14 oz.) can sweetened condensed milk
1/3 c. lemon juice
3 egg whites
1/4 tsp. cream of tartar
2 c. whipped topping

In medium bowl, combine milk and lemon juice; mix well. In small bowl, beat egg whites with cream of tartar until stiff but not dry. Gently fold into milk mixture. Pour into crust. Chill 3 hours. Top with whipped topping. Keep refrigerated.