MARY MITCHELL is president of Uncommon Courtesies, a Philadelphia-based business communications consulting firm. She writes a syndicated column called "Ms. Demeanor," is the Prodigy online manners expert, and is the author of The Complete Idiot's Guide to Etiquette and Dear Ms. Demeanor: The Young Person's Etiquette Guide. JOHN CORR is a writer with the Philadelphia Inquirer.