Line up the saltines on a foil-lined jelly roll pan. Make sure that the foil makes a bigger rim than the pan. There should be 5 rows of 8. Melt butter and sugar. Stir often and bring to a full rolling boil for 3 minutes. Pour over saltines and bake in a 400 degree oven for 5 minutes. Sprinkle with chocolate chips and wait until they are almost melted, then spread over all the saltines. Scatter the nuts evenly over the top. Refrigerate for a few hours then break into pieces.