Almost every U.S. tourist overseas knows that the place to change money, pick up the mail from home and meet fellow travelers is American Express. Famed as they are, however, the American Express offices in Paris, Rome, Tokyo and just about every other capital have never been the company's big profit makers. For many years, Amexco was really not much more than a bank with a tourist front. Lately it has branched into two dozen other areas of business, to become a sort of department store of financial and travel-related services.
The prime mover of the diversification is Chairman Howard...