We've already seen a number of celebrities, including John Malkovich and Zooey Deschanel, star in ads for iPhone's Siri.
Now director Martin Scorsese is using the Apple phone to reschedule his appointments and even spy on his friend Rick's whereabouts.
Other than being actually set in a cab, the ad includes a couple of welcome references to Scorsese's 'Taxi Driver'.
For one, number of the cab is the same as Robert De Niro's in the 1976 film. The second is a bit tougher to spot, but you can see a taxi resembling the original from the film whiz past.
We've already seen a number of celebrities, 
