Nope but its not the hotel, its the person that takes your reservation. He/She can be cool or a jerk. I did it as caesar palace and got a jacuzzi room for free which would of cost me an extra $100 bucks a night! You sandwich the $20 bill between your drivers license and credit card, but no i havent stayed at the PH yet to try!
That trick is a cruel joke. The only way to upgrade a room is to pay for it or deal with the hotel manager. The desk clerk has NO authority, money or not.