Heat oven to 200°F. Line 2 cookie sheets with parchment paper. In small bowl, combine egg whites and cream of tartar; beat at medium speed until foamy. Gradually add sugar, 1 tablespoon at a time, beating at high speed until meringue is very stiff and glossy, and sugar is dissolved.
Use disposable decorating bag or gallon-sized resealable food storage plastic bag with 1/2-inch hole cut in bottom corner. Spoon meringue into bag; twist top to partially close bag.
Squeeze bag to pipe meringue into 4-inch ghosts on parchment paper-lined cookie sheets. Place 3 chocolate chips in each ghost for eyes and mouth. Place cookie sheets on center rack in oven.
Bake at 200°F. for 2 hours. Cool 10 minutes or until completely cooled. Remove cookies from parchment paper.