Ok, so this isn't really San Francisco related, and I promise not to post things like this all too often (especially since it turns out to be a commercial at the end; so don't mind the last 3 seconds or so).
It is iPhone related however, which is inherently a San Franciscan's lifeblood so in an indirect way this kind of is San Francisco related.  But I digress, this video is pretty great, check it out: