Carefully crack the eggshell around the equator with the back edge of a knife. Holding one end in each hand, gently pry the two halves apart with your thumbnails, letting the yolk and whites fall into one of the halves. Holding both halves over a small bowl, gently pour the yolk back and forth from one to the other until all the whites slip into the bowl. The trick, of course is not to break the yolk. If you do, you can sometimes fish out the bits of yolk with a spoon. Otherwise, make scrambled eggs.