Stumbled upon this through Small Surfaces. A bunch of videos from Device Design Day, in San Francisco. You can find all videos here, but especially liked the one below by Dan Saffer. I liked it mostly for its brevity, because he is not the best speaker. But it's only 9 minutes long, and captures the way I perceive the way we think at Mobile Life. He says basically that we are part of the world, and by designing we change the world and therefore us. (Very very simplified, that I could go into length with.)

Design in the Post-PC Era from Kicker Studio on Vimeo.