And you forgot to add a category for the folks who are not using an iPhone, and are unlikely to ever do so.
On the rare occasion that I do carry a mobile phone, it is a $22 blue Nokia with a monochrome screen.
That is unlikely to change any time soon. A Mac Mini on my desk is about as far down the gadget road as I am ever going to get. I like to use a decent sized screen. My eyes and mitts, and lifestyle are not a fit for all those dainty, delicate little mobile gadgets.
Besides, I rather like the feeling of being off line the moment I walk away from my desk.