It’s amazing how many rumors have been blasting on for variety of iPhone designs now. That includes the 4″ screen one, which has pawned a significant amount of speculation and mockups about the possibilities.
In particular, the talk of a 4″ screen and rumors of an “edge to edge” screen resulted in this mockup by mjay2k which shows that a 4″ screen could fit on an existing iPhone 4 sized device by extending the screen to the left/right edges. Similarly a smaller iPhone could use the existing 3.5 screen in a similar fashion.
This image tries to look like a “spy” shot, but we believe is just another creative mockup.
Finally, this one is an old design mockup pre-dates the iPhone 4, but shows another take on a large screen format with a reduced prominence of the home button.