Multitouch was inevitable and demonstrated long before the iPhone. Mobile browsers existed long before the iPhone. What the iPhone did was have enough juice to run a real browser correctly. They did a good job on mobile Safari, but this is not a mind boggling invention. App Stores? Are you kidding? I had app stores on my smart phones for years. Yeah they sucked, but Apple didn't invent it, they just made it better.
Inertial scrolling, yeah, that's a good call, and the only one you mentioned that's a legitimate invention.
I'm not so sure multi-touch was inevitable. I mean, as a general concept perhaps. But the trend for phone during the time that the iPhone was released was tiny-keyboards. It was the Blackberry era. It's no accident that 2006 era Android protoypes looked like Blackberrys. Jobs made a point that they were going to do away with that, and go full screen multitouch.
It wasn't obvious and there were a lot of skeptics about giving up a physical keyboard. Typing on a screen just hadn't been done sucessfully.
You say this is obvious now, but what phone did you own in early 2007? I had a Palm Treo.... with a keyboard.
I guess when I mean multitouch was inevitable, I meant as a technology and not necessarily on the phone. Yes, Apple did perfect that technology first, but I saw demos of multitouch on tablet-like devices years before the iPhone. There were no commercial products that I can recall, but they were working prototypes and not just demos.
Inertial scrolling, yeah, that's a good call, and the only one you mentioned that's a legitimate invention.