While digging through pages of legal documents in the design lawsuit between Apple and Samsung, Yoni Heisler of Network World made a surprising discovery. Buried in the back and forth bantering of the legal team were several images of a prototype iPad that was created in the early 2000s.
During testimony in the case, Apple Senior VP of Industrial Design Jony Ive is asked to comment on these 3D tablet images. Ive says, "My recollection of first seeing it is very hazy, but it was, I'm guessing, sometime between 2002 and 2004, some but it was I remember seeing this and perhaps models similar to this when we were first exploring tablet designs that ultimately became the iPad."
According to research by Network World, this early prototype likely was created by Apple during a period of research into multi-touch glass displays. Though the tablet idea was cast aside temporarily, the design served as the basis for the iPhone.
You can read more about the history of this prototype and its discovery in the Network World article.