It's illegal to text while driving in Austin. I think such a law is unnecessary, as that type of behavior is already covered by other laws. That being said, I have been in the car with people who text while driving and it is somewhat frightening to watch them drift all over. People shouldn't do it, it's simply irresponsible when you're guiding a ton of metal at 60mph.
"Words are deeds." - Wittgenstein