Newton was the real OG, but Palm greatly simplified the concept and hit a lower price point, and was thus more successful. I had a succession of Palm Pilots and Handspring Visors, finally ending up with a Treo 650 before switching to an OG iPhone.
Now I'm remembering the awkwardness of that whole platform change. The Treo was a great, albeit bulky and heavy, PDA, but a mediocre phone. The original iPhone was amazing, but the hoops I had to jump through due to the lack of native third party apps was quite something.