Preheat oven to 250 degrees. Beat egg whites and salt until stif and forms peaks. Add sugar gradually, beating constantly. Beat until sugar is dissolved and meringue is glossy. Fold in nuts and vanilla. Reserve some nut halves to put on top of cookies. Spoon rounded teaspoonfuls onto waxed or brown paper lined cookie sheets. Top with extra nut halves. Bake in oven until cookies are pale ivory in color, 25-30 minutes. Remove from paper and pan at once, carefully. Cool on rack. May be stored in air-tight container.