Fast Forward

The Future and Its Enemies, by Virginia Postrel (Free Press, 272 pp., $25)

THE invention of the personal computer brought in one of those brief periods of explosive creativity when twenty-year-olds with no paper qualifications could make fortunes by inventing useful goods. Being a software developer in 1980 was like being a steam-locomotive engineer in 1820, or an aircraft designer ninety years later. Nowadays, of course, you need four