1 (14 oz.) can sweetened condensed milk
1/2 c. sour cream
1/2 c. freshly squeezed lime juice
1 tsp. grated lime rind
3/4 c. sour cream
1 tbsp. sugar
graham cracker crust

Combine condensed milk, sour cream, lime juice and grated lime rind. Stir well. Pour filling into a graham cracker crust. Refrigerate until firm. Stir sour cream with sugar. Carefully spread over top of pie filling. Chill.