"Hello world from comms center in #Pyongyang."
That Twitter missive, sent Monday from Koryolink's main service centre in downtown Pyongyang using my iPhone, marked a milestone for North Korea: it was believed to be the first tweet sent from a mobile phone 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 12 February nuclear test while the Associated Press's chief Asia photographer David Guttenfelder uploaded an image to Instagram of a tour guide at a mountain temple, geotagged to Pyongyang.
Pretty ordinary stuff in the world of social media, but revolutionary for North Korea, a country with intricate rules to stage manage the flow of images and information both inside and beyond its borders.
In the past, rules were strict for tourists visiting North Korea. On a bus journey across the demilitarised zone into the border city of Kaesong in 2008, we were told: no mobile phones, no long camera lenses, no shooting photos without permission. The curtains were drawn to prevent us from looking outside as we drove through the countryside, and through the cracks we could see soldiers stationed along the road with red flags. We were warned they'd raise those flags and stop the bus for inspection if they spotted a camera pointed out the window. As we left North Korea, immigration officials went through our cameras, clicking through the photos to make sure we weren't taking home any images that were objectionable.