Currently in Argentina it's illegal to talk with the cell phone while driving. After seeing the Mythbuster episode about it, I'm convinced that it's the right decision.
I still can't believe that in USA it's not illegal to text while driving. You have to look at the screen, you have to look at the keybord, ...
I think that the problem is that when a moron has an accident while using this app, the press will highlight that he/she was using this app while driving, not that the alternative of using plain texting would have be more dangerous.