I'm not sure what you mean by...

After having a friend getting an iPhone 4S yesterday, I realized how much I dislike the use of voice-command in public situations. It is outrageously rude to the people around (especially when you could just use the touch screen). I can fully understand the use of it in situations where you are alone, it mean be easier and doesn't disturb anyone else. I can even understand the use of it while driving or doing something that may need your utmost attention (Still may take too much attention away from the user still). But there is absolutely no reason to text someone using the voice command feature of your phone while with people. As I said before, it's just a party trick while doing it in front of people. And soon it's going to be a really old bad trick since everyone will have it sooner than later.
The worst part about voice command may be when the user has to repeat the same exact thing multiple times in order to do a simple task. It really grinds my gears.