I don't know about Iphone but I can only lament that my galaxyS2 is not built around the basic function. Which is or rather should be phonecalls. Well making a phonecall requires a swype gesture answering one also. Then the absence of a physical button for that requires you to look at the screen. In a perfect world I would say that those two facts contribute to deter people from phoning while driving but it's not the case and it only contributes to making people who phone while driving more dangerous as they look at screen and have to use two hands to answer calls or make them. On android when I got started, if the contacts was pushed to the groups tab it makes the phone tab disappear entirely. As a newcomer I didnt know where it went and for a few days I could only make phone calls from contact list. My point? in an emergency situation when you are stressed out, are wounded, for a reason have only one hand available ( say your arm is in a cast or you are carrying something) or using someone else's phone. Smartphones are ridiculously hard to use to start with.