I distinctly remember getting the first iPhone and, having come from some random Nokia, just staring at the vibrant iPhone screen. It seemed impossible. Similar reaction with the first iPads as well.
I'd been using a Windows CE device up till then, so the iPhone didn't really look revolutionary to me - the big deal was that the capacitive touchscreen made the interactivity model possible. You can't build the iPhone UI without that touchscreen - driving it with a stylus and a resistive touchscreen just wouldn't work.
Which is why I do get a little annoyed about the "Steve Jobs visionary" claims surrounding it - the market was circling the "single slate" concept for a good long while, the big innovation was finding a price-point and a way to manufacture the iPhone with that touchscreen technology and get it into consumers hands (and being willing to gamble on it).
Actually, I had a Dell handheld (Axim?) but never really found a use for it. I think it was the contrast and reactiveness of the iPhone that stunned me.
