I set my destination before I start driving and then just follow the verbal directions. If I need to change destinations or look something up, then I find I need to wait for a stop or else pull over. I don't do text messages when driving (I don't use them that often anyhow) but most of the proficient texters that I know use both hands to text. So I just can't see how it can be good practice to keep taking one's hands off the wheel when driving.