In a medium bowl, cream butter, sugar and salt. Continue creaming until light and fluffy. Add nuts and vanilla extract. Blend in flour gradually. Mix thoroughly. Shape into 1-inch balls and place on ungreased cookie sheets. Bake at 325 degrees for 15-20 minutes. Sprinkle some of the powdered sugar over cookies while still on the cookie sheets. Cool before removing from cookie sheets. Place some powdered sugar in a plastic bag and place some cookies in bag. Shake gently to cover complete cookie. Continue until all cookies are coated. Makes about 54 cookies.