If you are arriving late, ie. after 11pm (when late shift hands over to night shift), please call the hotel early to let them know u are arriving late. Reason being, the night shift actually shuts down the property management system for night audit, and at the hotel where I used to work for, guests who do not turn up by the time night audit is conducted would have their reservations cancelled. (Although there are contingencies in place for the late arriving guests). While it does not make your reservation more guaranteed than others, or prevent you from getting walked in a full hotel, it does lower the probability of those two incidences happening, especially the 2nd.

I know this is slightly OT, but it was somethiing that came up in my mind when I was going through this thread.