I'll suggest the smartphone was inevitable.
Computer technology became better, chip makers became more efficient at packing more stuff into smaller sections of silicon real estate, speed improvements and lower power requirements made the web in your hands possible, and the public wanted more crap in their hands like YouTube, SMS, the Web, HD Video, and perhaps a phone call or two.
Apple hit a home run with the iPod. But I had a Sony Walkman and a Sony MiniDisc recorder long before the iPod gave digital music to the world. Music was always with me in the form of cassette tapes and mini Laser Discs. Apple did not invent these ideas, but they made digital music what it is today. Apple gets credit for creating something that the public took seriously and I'll suggest that all other MP3 players are here because of Apple's creations.
Perhaps RCA gets credit for new ways to record and play music and video. They offered Wire Recorders for audio and Capacitance Electronic Discs for Video. Or does Pioneer get credit for video on a disc with their Laser Vision products, or T. A. Edison for music before that, with the invention of his Gramophone? I can play a nice waltz on a piano that uses a mechanical and pneumatic system to read from a roll of paper, I was sending "digital" communications before Apple and the rest created their devices, so the idea of digital communications (of a sort) is not new.
I can listen to digital messages (of a sort) with my Continental Instructograph. Did Continental invent digital messaging? Perhaps Samuel Morse gets credit for "digital" (Binary might be more accurate because we use dots and dashes which equate to yes/no or on/off) communications and everyone stole from him. Or perhaps Morse ripped off someone else.
"Franklin Pope was a telegraph inventor and writer. He may best known for his partnership with Thomas Edison in the telegraph services in early of 1870. Alfred Vail was one of Samuel Morse's partners and contributor in the development of telegraph. William Baxter was Vail's lab assistant at the Speedwell Iron Works where early developments were made." So who invented it? History credits Morse, but who is to say if he invented it, stole it, or simply took credit for it? Long time ago and he did not work alone.
So at what point did the smartphone arrive and who gets the credit? What features make a cell phone a smart phone? Who created the first such device? Radio telephones are not new; I posted a picture of one from the 1920's. Did Apple copy the idea or did the Brick Phones start us down the road towards the smartphone and technology improvements made the idea feasible and the general public that wanted more and more and more drove innovation?
What about Palm? We put email, up to date stock reports, weather information, travel aids, and the web in your hands before the iPhone arrived and we ran a few PVTs for RIM that clearly pointed a way to a smart telephone type device. But we also built products for the Newton which also gave you web and email access but no phone. Had the Newton been a huge hit, Apple most likely would have found a way to add a telephone because lots of people in the know, me included, wanted to see a phone incorporated into Palm devices because it seemed logical.
John Sculley coined the term PDA so Apple did indeed "invent" the PDA but Palm glorified and elevated it to a high level. It has/had much in common with the smartphone of today, so does Apple get credit for leading us towards these types of devices? Yes. Did Palm steal Apple's ideas and use them to create a far better PDA? No.
I'll bet very few people gathered here ever saw a Newton. Just Me and EarlyMon, perhaps.
So at what point do we say Company A invented this or that and give them credit rather than just say they copied and greatly improved an idea? Does the credit go to the inventor or the innovator that took an idea and made it better and manufacturable?
Who cares, we all benefited from those that came before us.
Bob