I love traditions, well sometimes. As a child, I remember putting on nice clothes when the family went shopping at Sears. I like the idea of dressing up when you go out and think the world would be just a touch nicer if people continued this concept of respecting others in their own actions.
Another idea I like is saying, "Excuse me" before answering the telephone. I find it rude when a call from a stranger takes precedence over my presence.
I remember phone booths that closed around you, and I think that was a good idea also. And I think it rude when people do a lot of talking on cell phones in public places. To that end, here's a link that fights the rudeness of talking to loud on a cell phone with a new kind of rudeness. Not necessarily the best approach, but it's something.