I gave a talk "3 years of OSM Buildings" at State of the Map US conference June 2015 at United Nations Head Quarters in New York City. That's a lot of big names and it was even more visitors with big names. I'll write anther post about my impressions.
But first the talk, recorded and uploaded by the great organizing team.
Talk video, all in one.
Demo video, shown during the talk.
Slides as PDF, shown during the talk