I remember being very excited about these devices (and others like the Treo) before they were released, then invariably found myself profoundly disappointed (or at the very least underwhelmed) when I actually got my hands on one.
None of them really succeeded in delivering anything more than an iPaq or a Palm Pilot and a mobile phone awkwardly squashed together in an ugly package, and they all required you to use a stylus that all-too-frequently got lost or broken. In the case of the 770, it didn't even have a phone! (To be fair though, in its favour it was the first device I saw that had a really good mobile web browser app).
Until the iPhone, "smartphone" really meant putting "groupware" [1] functionality in a mobile phone, and just having an Outlook-a-like on a phone clearly wasn't appealing enough for the mass market: in fact it was just downright boring...
The biggest difference with the iPhone aside from the capacitive touch was that it delivered an excellent mobile web browser alongside a reasonably decent phone, and all that other stuff was just an afterthought.
In retrospect I'm amazed that nobody else realised that the web - the same technology that transformed the internet from a niche technology into a must-have in the mid-90's - was the killer app for a smartphone (As I alluded to above though, kudos to Ari Jaaksi's team for at least trying with the N770 etc., even though the rest of Nokia seemed to be utterly clueless).
Most user friendly device before iPhone was probably Danger's HipTop aka T-Mobile Sidekick. It was actually fun to use, and innovated smartphone usability in huge number of ways. But it seemed marketed as more of a toy, too bad.
Let's not forget a number of PocketPC touch (stylus) devices were also phone-capable. That was YEARS before the iPhone. It had "apps" too, but we simply used to called that "programs" at that time. And there was no central market/appstore or anything. Most of these devices were very open.
Had one of first Compaq iPaq GPRS sleeves, ordered directly from Hong Kong before US availability. (Late 2001, early 2002.) And Handango was my "app store" of choice.
The 5 years from 2002 to 2007 were interesting, but in hindsight seem to share so little with post iPhone industry.
It clearly did not reach critical mass at that time. There were a number of obstacles to adoption - devices were powerful enough to do things, but compatibility with office software was not well built-in (If I remember correctly you could not synchronize emails with Outlook right out of the box). But third party applications were often very good and feature-plenty. The media players were especially capable and well designed.
It was however, impossible to upgrade the software at that time (the OS), which rendered your device obsolete every time a major WindowsMobile version was released. This is happening again with Android and I can't say this is a very good idea.
The interface on those was more of a barely usable desktop experience, that happened to use a stylus. You could not call it a "touch interface". My brother had a HP Jornada, and while he used through college, it was kind of sucky. It ran Doom, though.
I disagree. Those devices were very usable but, of course, you needed 2 hands to do anything with them. You could do a lot of stuff with it, and a number of apps were way more advanced than what you see on android and ios nowadays. The finger interface has got much better, but a stylus was way more precise for many purposes. The surface covered by a finger induces great limitations to the interfaces you can create. There's no miracle.
The funny part is that I know a lot of people that miss having a stylus... so much so that many are buying them now for their phones. I miss having one every time I have to take off a glove to interact with the nav app on my phone.
