Preheat oven to 250 degrees. Using electric mixer, beat whites in a medium bowl at high speed until foamy. Add salt and cream of tartar and beat until soft peaks form. Add sugar, 1 TBS at a time, beating well after each addition. When meringue is stiff, remove bowl from mixer, and fold in vanilla and chocolate. Drop by teaspoonfuls onto lightly greased baking sheets, or use Silpat. Bake 40 minutes. Cool on rack, and store in airtight container. 5 dozen cookies.