In the picture above you can see two iPhone prototypes that Apple was working on way back in 2006. They provide an amazing glimpse of just how long the prototyping phases of iPhones can last, because the original iPhone didn’t come out till June 2007, and then the iPhone 4 wasn’t seen till 2010.
The prototype images come from court filings in the Samsung vs Apple legal proceedings where Samsung plans to argue that Apple ripped off Sony’s design as inspiration for the iPhone. In fact, a few of the renders for the iPhone 4 like device have the Sony logo on them as you can see below: