Combine graham cracker crumbs, melted butter or margarine, and 3 tablespoons white sugar. Mix well. Press into a 9 inch pie plate. Place in freezer.
Beat together half and half and 1/2 cup white sugar for about 2 minutes. Add undiluted orange juice concentrate, cinnamon, and nutmeg. Beat for 1 minute. Add ice cream, and beat an additional 2 minutes. Pour filling into prepared pie crust.
Freeze for several hours or overnight. Just before serving, garnish with whipped cream and orange sections if desired.