While not as significant as eradicating smallpox, the launch of the first cell phone network in 1979 is significant. Not so much for developed countries, which already had good wired phone service, but for developing countries, which leapfrogged past the challenges of deploying copper wire.
Matthew DownhourI like this brainstorm: greatest achievements since 1969. Number one for me: eradicating smallpox What else?