1. Beat egg whites with cream of tartar until foamy in a small deep bowl.
2. Gradually beat in sugar to make a stiff meringue.
3. Fold in plain "M&M's".
4. Grease and flour a large cookie sheet.
5. Drop meringue mixture by teaspoonfuls onto the cookie sheet. Garnish each with a plain "M&M".
6. Bake in a low oven (250 degrees) for 30 minutes, or until cookies are firm to the touch, but still white.