The computer has gone through several metamorphoses since all of us began to make room for it on our desktops more than a decade ago. First it was a nimble and versatile typewriter, then a hefty number cruncher, and now it is becoming the ultimate communications device, connected by modem and telephone lines to an amorphous global network called the Internet. I eagerly invested in one of the earliest personal computers, a quaint little machine that I now realize was the research equivalent of training wheels. I also bought a modem when such devices were little more than clumsy novelties and dutifully plugged into a telephone jack, only to discover there was nothing of any significance on the other end of the line.