Take this one with a huge grain of salt, but according to a Chinese site called C Technology, the following blurry image shows the frame of Apple's next iPhone:
We first spotted this one on 9to5Mac. The image shows a smartphone frame that's significantly larger and thinner than the iPhone 5S body. C Technology has a so-so record with Apple leaks, so it's worth at least mentioning.
To be clear, we have no idea if this is real or not. All we know is that this image comes from a somewhat reliable source of Apple rumors out of China.
It could also just be a random hunk of metal someone took a photo of.
We also know, via The Wall Street Journal and other publications, that Apple is playing around with big-screen iPhones, some with screens as large as six inches. (The iPhone 5S has a 4-inch screen.) And there's a good chance that 2014 will be the year Apple finally makes a phone with a screen large enough to match phones from rivals like Samsung.