And that, of course, was the point. "We wanted to do a dazzling demonstration," Cooper said. The team's goal wasn't just to invent something; it was to let the world know, in as striking a way as possible, that the something had been invented. The demo would end, appropriately, with the technologist processing to the Midtown Hilton, where a gaggle of reporters was assembled for a press conference. Cooper would hand his phone to one of those reporters so she could call her mother in Australia.

Cooper, in other words, enjoyed -- and exploited -- the moment. "I made numerous calls," he remembered, "including one where I crossed the street while talking to a New York radio reporter -- probably one of the more dangerous things I have ever done in my life."

'What the Hell's a Portable Cell Phone?'

The technology that fueled Cooper's demo had been in the works, of course, long before Cooper strode out onto 6th Avenue. (Cooper knew the phone would work because, on a trip to Washington, he had previously demonstrated the technology for the group that was arguably his most important audience: the FCC.) The cell phone was the culmination of a good, old-fashioned race to invention, much like the one that led to the telephone itself. And it was spurred along not only by competition among R&D departments at rival corporations, but also by a broad sense of technological progress -- progress that would be inevitable if only consumer hardware could catch up to it. As early as 1947, engineers at Bell Labs had imagined the standard cellular network. By the 1970s, car phones -- the original mobile phones -- were in regular, if not widespread, use. Human-centered mobile phones, Cooper thought, were the next obvious step in telephony's evolution.

But that wasn't obvious to everyone. The Federal Communications Commission, at the time, was deliberating whether to allow AT&T to set up a network that would provide wireless phone service in local markets, ostensibly for use with car phones. Not only, Cooper knew, would this proposal give AT&T an effective monopoly in those markets; it would also mean that car phones, rather than hand-held, would likely become the dominant mobile technology. Cooper and his colleagues saw where things might be heading -- so they decided to intervene. They charted a new destination, and then set their sights on leading the way there. But they had to hurry.

Rudy Krolopp, lead designer of the device that would become the DynaTAC, recalled the frantic weeks that led, finally, to the cell phone. "Marty called me to his office one day in December 1972 and said, 'We've got to build a portable cell phone,'" Krolopp says. "And I said, 'What the hell's a portable cell phone?'"