Melt chocolate over hot, not boiling water. (Or 30 seconds on High in microwave, stir then another 30 seconds.)
Beat egg whites with a dash of salt until foamy. Gradually add sugar, beating well, then beat until stiff peaks form.
Beat in vanilla and vinegar. Fold in melted chocolate and nuts.
Drop by teaspoonfuls on well greased cookie sheet. Bake at 350 degrees F (180 degrees C) for 10+ minutes. Remove from pan *immediately*. Decorate with nuts if desired.
