Windows had it, Mac OS had it, newtons had it.. shoot those functions have been givens on electronic devices for decades now man.
You can give Apple credit for creating the Newton and the iPhone. A lot of things on the iPhone evolved from.. things that already existed elsewhere. If you really want to reach deep you could give them credit for lots of those things via the Newton and some other R&D they did.
By far and large though, the a rectangular slate with few/no buttons was not a new thing brought to the world by Apple with the smartphone - in part because that's what the newton was lol.
You also can't really give them credit for inventing and bringing capacitive touch to the world - that would have come out anyway (as it did with the LG Prada). Perhaps it would have taken longer to catch on, but it would have happened.
The problem with resistive touch was that unless you had your stylus handy, or your hands were clean or something - it wasn't entirely reliable (you know this). That's why phones before the iPhone had accept/hang up buttons on the front, along with some other simple navigation buttons.
Even then, some didn't. The Sony P800, for example:
http://tamss60.tamoggemon.com/contents/2010/February/tha800/sony-ericsson-p800.jpg
I don't think Sony had a spy in Apple's HQ looking at the iPad prototype going EUREKA! I MUST HAVE SONY COME OUT WITH THIS FIRST!
(that, and the iPad was probably a skunkwork type project that had been going on since the 80s). That's ok by me, though I still think the tablet platform has a long way to go. We keep falling back on things like copy/paste and desktops and overlapping windows because they work, not because we're a bunch of lazy bums that can't come up with anything better.