The arrival of voice technology that works marks an inflection point in computing. After a month of using Siri, the new voice-controlled “personal assistant” available on the iPhone 4S, I’ve decided it may be time to add voice control to the list of paradigm-shifting ways to interact with a computer — right behind the mouse, keyboard and, more recently, touch gestures. While voice control remains far from perfect, the ease of use and instant results Siri delivers may be just enough to shift people’s habits. It’s certainly changed mine.