You need a large antenna for NFC: http://www.ifixit.com/Teardown/Nexus-S-Teardown/4365/1#s20138 http://www.ifixit.com/Teardown/Nexus-S-Teardown/4365/1#s2013...

You need a large antenna for NFC: http://www.ifixit.com/Teardown/Nexus-S-Teardown/4365/1#s20138 http://www.ifixit.com/Teardown/Nexus-S-Teardown/4365/1#s2013... (hover over the second picture on Step 3) Even if a chip existed, the iPhone 5's aluminum back wouldn't provide a spot to place an NFC antenna.