Why is the iPhone 5 magnetic on the back near the camera lens? The iPhone 5 magnetic enough on the back near the camera lens to attach a staple to. Why there is a magnet there and what it is for?
It's very likely to be the speaker. Because yes, speaker use magnets. 

It's on opposite side of the top speaker only and looking at this picture (courtesy of iFixit's iPhone teardown) there is nothing else that is magnetic.