Preheat oven to 350 degrees F (175 degrees C). Generously grease a cookie sheet or line with parchment paper.
Blend egg whites and salt with an electric mixer until peaks begin to form. With the mixer still running, gradually add sugar, 1 tablespoon at a time, until all is incorporated, then add the cream of tartar.
Gently fold in chocolate chips using a wooden spoon or rubber spatula. Using a teaspoon, drop batter onto prepared cookie sheet. Place in the oven, and turn off heat. Leave in the oven at least 4 hours, or overnight for even better results.