If you know your bit of technology history, you'd know that Apple was actually working on an iPad before it developed the iPhone. What did those iPad prototypes look like? Well, according to these earliest known photos of an iPad prototype from the early 2000's, it looked really, really fat.
There's definitely hints of the old MacBook in it and the ethos of the current iPad is all there but boy, from these pictures, this iPad prototype, called Prototype 035, was much, much thicker—like a heavy hardcover book as opposed to the light magazine thinness it is today. Network World cleverly dug up the mockup of the iPad prototype by examining the court filings of Apple and Samsung's legal battles. Jonathan Ive even pitched in at court (he was deposed by Samsung) to discuss the mockup:
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.
So Apple had been working on the iPad for almost a decade, starting in 2002 and then finally delivering it in 2010 with the original iPad. It was worth the wait, if only so it didn't feel like we were working out our biceps every time we picked up this fatty prototype.