Elevator Etiquette

So I've been thinking about this ever since I moved into my latest apartment. It's a doorman elevator building with 2 elevators and 26 floors. I happen to live on the 23rd floor (With a great view in case you're wondering or want to visit.) so there is plenty of opportunity for me to share some elevator time with strangers.

What is the protocol in the elevators when a stranger enters the elevator? Do you say hello? Do you strike up a conversation? Do you wish them a good day/night? Or do you look at the floor and fumble with your phone/thumb through your mail?

I am guilty of all of these and quite frankly I think it's a nice thing to at least recognize the other person in the elevator with you. I try to at least say have a good day/night when they arrive on their floor/I depart to mine. Too many people go through life without thinking about the little things, who knows it may have made someones day to say something as easy as have a good day.

On the other hand when there are 2 people or more going to different floors all bets are off. If you're the first person off the elevator it's okay to give the remaining people in the elevator good wishes but it just seems weird the other way around.

What are your thoughts on elevator etiquette? This is something I'm definitely intrigued by, and I routinely am amazed by behavior that occurs in elevators.

Lastly, I'll leave you with this. I would never wish to be in this position and thankfully have never been stuck in an elevator, I'd definitely have a panic attack and try climb out the top.