On the Treo 650, for instance, making a call meant hitting Send (a hard key) from anywhere in the UI, typing a name to start a live search - you did not need to focus into a text box first - and hitting Send again to start the call. Likewise, if I wanted to send a text message, I'd hit the SMS button, start typing a name, hit Select to open that conversation, and then start typing the message. The device had a touchscreen, but for the most common activities, you didn't need it.
The 650 did not have built-in Wi-Fi, but with the Enfora Wi-Fi Sled and Opera Mobile, Web browsing was actually a decent experience. Likewise, I had some basic networked apps like AIM on there.
Before the 650, I had a Handspring Visor and the VisorPhone attachment. The VisorPhone was way ahead of its time, but what finally killed that for me was a side effect of Palm devices not having memory protection. If someone sent me an MMS message, the entire thing would immediately freeze (it had no MMS support, and didn't handle receiving one gracefully). I'd have to take the batteries out to reset it. As more and more people did this, it became a more frequent occurrence.