When we write characters, most of us know it's important for them to say more than "Good Morning", "How are you", and those types of things. Meaningless phrases of etiquette aren't necessary and are usually boring, unless they have an underlying reason.
Subtext is a fascinating way to use dialogue. I actually just saw it used in a brilliant way at the end of a movie. That's for my next post.
Today I'm in Orlando, attending a writer thing to learn writerly stuff from some authors. I'm very excited, especially since one author is teaching about characterization, a personal nemesis of mine.
If you have time, click on that link for subtext and read about it. Have you seen it employed recently? In what and how? Did you find it effective?