Thought-provoking, but calling it “no UI” is a reductionist view of what UI is. Let’s not forget that “UI” stands for “user interface” — and if the interface is SMS then that’s the UI. Throw out “UI” if you must and return to Ye Olde Classick “HCI” but let’s not lose sight that even a the smoke detector in your house has a UI — even if it’s “just” a little light, a button, and some annoying-ass low-battery chirps at 3 in the goddamn morning.