Apple is considering a range of possible options for expanding its iPhone lineup in 2014, say four sources for Reuters, some of which are said to be with Asian suppliers. The people claim that Apple is considering two bigger iPhone sizes, including 4.7- and even 5.7-inch sizes. Suppliers have reportedly been approached with plans for the bigger screens, but whether or not they'll make it into shipping products is uncertain. "They constantly change product specifications almost to the final moment, so you're not really sure whether this is the final prototype," one source says.