I'm a newbie to backpacking but I've used powdered milk in recipes at home for hot coco, creamy instant soups ect...

In The Complete Walker IV by Colin Fletcher he states using powdered milk for a lot of the same things others have stated. He also says to use a squeeze bottle ( like ketchup and mustard are kept in at hot dig stands or picnics) to store the powdered milk in, suppose to be easier to store and dose.