Um, who's the parent here? How young is this youngest you are speaking of?
Actually, I do not have to get used it. If one of our kids has one of our cellphones (which would only be for the purpose of being in contact with us), and they didn't respond when called, or call when expected, they'd be grounded. Period, end of discussion.
He's 18 and of course I'm the parent. My wife and I are fairly relaxed parents, we don't set lots of rules, and as a consequence our kids have never been in any kind of trouble, unlike the kids of some more controlling parents we know. But back to the topic, I find texting to be pretty simple on my Iphone and a good way to quickly dash off a simple message. If all I want to know is, say, "Where r u" I don't need to make a call, wait for it to ring, etc. It's actually very efficient.