SMS has become my default method of communicating with colleagues, especially when traveling to trade shows. At some super-secret press conference and can't talk? Send an SMS. At a swanky dinner and would look like a rude oaf to get up to make a call? Send an SMS. On a noisy trade show floor and can't hear anything? Send an SMS. One night, I was with a handful of colleagues and we were all having private SMS conversations with one another even though we were all standing there speaking face to face in a group.
As much as I use SMS, though, I've never used it to relay super important or sensitive messages. Firing someone? C'mon. Man up and do it face to face. Breaking up? Well, that one's more tricky, but an actual phone call is the least you can do. Flirting? Sounds harmless...if you're single.
You see, as fun as SMS is, it removes the personal element from communicating with one another even more so than e-mail. It takes almost no thought or emotion to whip up a text message, hit send, and continue on with your life. Maybe that is a bad thing, maybe it isn't.
Either way, SMS has arrived. It's a mainstream form of communicating, and a vital one. Just don't abuse that impersonal power.