Apple has released another ad for the iPhone 4S and its biggest selling point, the Siri voice assistant. The new commercial stars film director Martin Scorsese driving into downtown New York City for a busy day, and using Siri to help him reorganize his schedule, check on traffic, and identify the whereabouts of a friend. The ad is the first to show Apple's "Find a Friend" app in action, pointing out that Siri can leverage the program in response to a question such as "where's Rick?"