At TEDGlobal 2011, portraitist Siegfried Woldhek sat down in the Autodesk Café with an iPad and some special drawing software, and proceeded to sketch, with lightning speed, anyone who took a seat in front of him. You can see his work in his iPad Portraits Flickr set — attendees, TEDx hosts, Coffee Common baristas, and TED Fellows, all sketched in his inimitable style.