Preheat the oven to 375 degrees F (190 degrees C). Sift together the flour, baking soda and salt; set aside.
In a large bowl, cream together the butter and sugar until smooth. Beat in the eggs, one at a time then stir in the vanilla. Blend in the sifted ingredients to form a soft dough. Stir in the chocolate chips, white chocolate chips and walnuts. Drop by heaping teaspoonfuls about 2 inches apart onto ungreased baking sheets.
Bake for 8 to 11 minutes in the preheated oven, or until lightly golden. Allow cookies to cool on baking sheet for 5 minutes before removing to a wire rack to cool completely.