Phone call. If it's not important enough to say it with your voice to the person, it's really not worth saying. If you don't like them enough to want to talk to them on the phone, you shouldn't be talking to them regardless.
I consider every phonecall I make to be worthwhile, even if it will only take a few minutes. And the people I call, I call for a reason. Not to mention, texting sucks for those of us who want to use proper punctuation and grammar. Even with a full keyboard phone...I hate those types of phones.
In addition, I used to work as a high school janitor. And I can tell you this very simply, and very matter-of-factly: Texting is make America less intelligent. Or at least, less literate.