iPhone 5 leaked picture of a larger display
This image from fast company is suggesting that the iPhone 5 rumor of having a very large screen going through side by side the device is true. Screen size is speculated at 4".
The phone's physical size is very similar to iPhone 4 but the they manage to include a larger screen by minimizing the bezel and making use of the wasted space near the menu button and the ear piece.
From Fast Company