Or, smart enough to realize that almost anything that can be said in 160 characters or less, really isn't worth saying at all.
"Hey, do you wanna to go camping this weekend?"
"Shit, I'm gonna be a few minutes late for our meeting"
Or even something as simple as "Happy Birthday!".
Yeah, I can't possibly think of any use for a communication medium that is terse.
I swear, I'm as much of an old grumpy fuck as the next Slashdotter - but even I recognize something that's ubiquitous, simple, and damned handy. Email is more involved, calling has its own issues (not everyone is free to engage in a call every second of the day), IM is nowhere near standardized...
Gimme SMS text for making plans with people or blasting off quick info, thanks. It's one of the best technologies invented in terms of "it just works". Well, presuming most people have cellphones (insert a bunch of comments below about how you don't own a TV either, and we may have another Onion article on our hands).
Contrary to what some kids seem to think these days, SMS texting is not Twitter. I'm not sending "I'm taking a dump!" to my friends through SMS (although perhaps I should...).