Here’s my rules:
Normal situation, I go through and hold the door so it won’t hit the next person in the face.
With family and friends, a more social setting, I hold the door and allow them to go through.
When I’m not rushed, I also hold the door and allow others to go through. Although, if I had a video recording of every time I ever did this, it would probably show a tendancy to to this more often for women… as I’m checking out their posterior.
::shruggs:: What’s a guy to do?
I held the door for a much younger woman than I yesterday. She breezed through like she expected it, didn’t glance at me, didn’t say thanks, just held her head high and waltzed through the door. At the time I didn’t figure it was worth it to say “thank you” out loud and show her what an ass she was. I should’a. She was an ass. Carried herself with quite the queenly air. Ass.
Rules? For every door you open for somebody, a window is closed. Or something like that. 
My response in this situation is a loud “You’re welcome!”
Not only do I thank men who hold the door for me, I bat my eyeslashes at them 
Women get the thanks only.
My wife and other friends have often teased me about collecting tips. I tend to be a little…anxious about not letting a door go in someone’s face. I know I’m over the top because I’ll occasionally be walking with someone, hold the door open for them, and then they wonder where I’ve disappeared to because I was holding the door open for the next four or five or six people after them. :smack:
But no one would ever accuse me of not making an effort. 
And gender isn’t really a factor for me. I think letting a door go in anyone’s face is incredibly rude.
It’s just common courtesy as far as I’m concerned. I hold the door for anybody if they’re close enough behind me to make it practical. I don’t usually hold it open and let them pass first, but hold it until they can get ahold of it. Door holding is pretty uncommon in Japan, no tradition for that particular courtesy, but I still do it a lot of the time. And yes, if it’s a woman and she’s kind of cute I do sometimes let her go through and then check out her ass. Of course, the ass-checking is more of a reflex than anything
What Dad taught me:
If two people of similar age, neither of them carrying a load or pushing a pram, approach a door at the same time from the same side, whomever reached it first keeps it open for the other. When leaving any kind of meeting hall (where the aforementioned happens for a lot of people, not just two), hold the door just enough to ensure that the next person “has it”; pay attention to when the person in front of you “passes it”.
If from opposite sides, the one who approached it from the “pull” side holds it.
If one has any kind of mobility problems (heavy load, old age, broken leg, pushing a pram…), the other one holds it.
What several guys taught me:
If you never hold a door for anyone and want to look chivalrous in front of a lady… learn how to do it before you start! I kept getting these guys who would cross my path in order to reach the door before I did, then instead of grabbing its handle (or the edge of the pane, if there is no handle) and standing behind the open pane they’d push it with their arm across the way. The idea is to ease passage, not impede it.
When St Pete closes the door, Mary opens a side window.
Rumour has it that it’s a bathroom window but this hasn’t been confirmed.