The story about how Boeing convinced the FAA to certify the 767 and 777 cockpit configuration (pilot and copilot only) is an interesting one. On the flight-safety test, Boeing had a 777 take off, fly a prescribed route, and land with *nobody* in the cockpit. That convinced the FAA that a flight navigator was not necessary in the cockpit of those aircraft.
^ Meant to write 757 and 767, although I recall that the 777 has a two-person cockpit configuration as well.