1 graham cracker pie crust
1 can sweetened condensed milk
1/3 c. lemon juice, fresh or bottled
3 egg whites
1/4 tsp. cream of tartar
2 c. Cool Whip

Combine milk and lemon juice, mix well. Beat egg whites with tartar until stiff but not dry. Fold Cool Whip and egg whites into milk mixture. Pour into crust and chill 3 hours.