A bit OT (not SPG-related), but... I just had a conversation about this today with a taxi driver on the way to BUR from the nearby Courtyard Marriott. He said that the shuttle vans to LAX have to pay the hotel $20 to pick up pax (the charge is passed on to the customers). He also muttered something about hotels that expect payment for calling a particular cab company, but I couldn't completely follow everything he was saying on the subject.