What are some things that you consider to be common courtesy that aren't all that common?

3 examples to start you off.

1. Like on the highway, I stay on the right side of a sidewalk, using the left side only to pass, so I get annoyed when someone decides to use the left side, or worse walk down the middle of the sidewalk.

2. Most sidewalks are designed so that two people in opposite directions can walk comfortably. So if my husband and I are walking side by side and we see someone approaching from the opposite direction, I will step in front of or behind my husband to make room. Quite a few couples refuse to do this.

3. This one is a story. Last night, I was in the elevator, about to take the dog out. Just before we reach the lobby, I always go towards the door so that I can leave quickly to allow others on. My dog likes to be right up to the door. When we reached the lobby and the doors open, there was a little old lady that was standing so close that her nose must have been touching the door and she freaked when she saw my dog so close to her. I told her that if she stood back to allow people off, maybe she wouldn't piss herself.

So, what are yours?