I don't, it doesn't "feel" right in the hand or to the eye to me.
I never thought I would like a camera without a view finder.
I use the iPhone only for things it can do well - primarily I like to do nature shots; wildlife, flowers, and the wide-angle lens in the iPhone is useless for that, since it does not have an optical zoom. Usually I need a tele lens or macro lens.
I use the iPhone for panoramic shots, because my camera does not stitch panos, and I use it for geocoding, and for architecture or landscape photos. It does not feel right in the hand, but it is easier hold steady if I do not have a tripod with me. I can press it against any flat surface and still see what it is focussed at on the screen. Perfect for taking photos through a window pane, a fence, or the showcases in a museum.