Incentive industry veteran Jim Feldman knows a thi ng or two about travel--and marketing. To promote his new book, Doctor Travel's Cure for the Common Trip (Sage Creek Press, 1999), at the fall IT&ME Show in Chicago, the president of Incentive Travelers Cheque Intl. donned doctor's whites and stethoscope and handed out doctor's bags with snacks and the book. Just as many people showed up for the book as for the munchies: Its 27 chapters are packed with tips on everything from passing the time at airports to avoiding jet lag. E-mail jfeldman@doctortravel.com.