Apple's dramatic uptick
in iPhone sales in the final calendar quarter of 2012 put its two leading iPhone models -- the iPhone 5 and the iPhone 4S -- at the top of the heap as the current most popular smartphone models in the world
, according to handset industry monitoring firm Strategy Analytics
. Together, the two iPhone models sold over 44.8 million units in Q4, handily surpassing its nearest rival, Samsung's Galaxy S III (which shipped 15.4 million units, a sizeable decline from the prior quarter).