Preheat oven to 350 degrees. Line a large cookie sheet (with sides) with saltine crackers, having edges touching. In a medium saucepan, melt butter and sugar together. Bring to low boil, and simmer until mixture is white and frothy. Pour butter mixture over saltines, using a spatula to spread and cover all crackers. Bake 10 minutes or until golden brown. Remove from oven and sprinkle chips over crackers. Return baking sheet to oven for 1-2 minutes until chips soften. Remove from oven and spread white chocolate evenly over saltines. Sprinkle with nuts, and if desired, red and green sugar crystals. Refrigerate or freeze until hard. Break into small pieces.