“Hello world from comms center in (hash)Pyongyang.”

That Twitter missive, sent Monday from Koryolink’s main service center in downtown Pyongyang using my iPhone, marked a milestone for North Korea: It was believed to be the first tweet sent from a cellphone using the country’s new 3G mobile data service.

Later, as we were driving through Pyongyang, I used my iPhone to snap a photo of a new roadside banner referring to North Korea’s controversial Feb. 12 nuclear test while AP’s Chief Asia photographer David Guttenfelder shot an image of a commuter walking beneath a bridge at dusk. We uploaded these images to Instagram geotagged “Pyongyang.”

Pretty ordinary stuff in the world of social media, but revolutionary for North Korea, a country with an intricate set of rules designed to stage manage the flow of images and information both inside and beyond its borders.

Leader Kim Jong Un has pushed science and technology as major policy directives, and we’re starting to see more laptops in offices. But the World Wide Web remains strictly off limits for most North Koreans. North Korean universities have their own Intranet system, although the material is closely vetted by authorities.