By the 1990s Americans were already becoming immersed in the technology of the digital economy. "The distinction between software and money is disappearing," declared William Niskanen, chairman of the CATO Institute. If cyberspace really is "the final frontier of finance," then cash began to go where no money had gone before. MasterCard, for example, invested millions to develop an e-cash system called Mondex; its cards are embedded with a microchip that can store not only electronic dollars but also five other types of currency, an abbreviated medical history, and a personalized electronic key that can unlock the doors of the cardholder's apartment, house, and office. "The chip that we are putting on the card now will form the platform for the ultimate in remote access for consumers to their funds, anytime, anywhere," said Henry Mundt, MasterCard executive vice president for global...