Here is some old, but very relevant, material I posted on another thread related to walking:
For situations where I know I will be arriving at 10 PM or later, I usually have that put into the reservation when I make it. If I will be arriving after 11 PM, I not only note the reservation, but will usually call the hotel sometime the day of arrival to let them know I will be in that late. If I plan on arriving very late, say after midnight, I will call the hotel twice, once early in the day and once in the evening (8 PM or so if possible). If I have a late arrival and something happens that will make me even later (flight delay, etc.), I will call the hotel again to let them know my situation, when I believe I will arrive, and specifically request that my room be held.
It isn't often that I arrive after 11 PM, so I don't end up making many calls, but on a number of occasions calling has saved me. I've seen situations where the hotel has checked me in before arrival, based on my call, and then walked multiple people checking in at the same time as me. It's a pain to have to call, but it does help.
It's nice to see a good common sense solution to this problem. Although sometimes tough to remember or do in the rush-rush of business travel. Thanks.