A friend of mine worked at a bank and used early Nokia Communicator to remotely administer machines including AS/400. He could do it from his bed while on stand

A friend of mine worked at a bank and used early Nokia Communicator to remotely administer machines including AS/400. He could do it from his bed while on standby, or while on the go. An absolute game changer. That it had a browser is more of an afterthought. And of course it is slow; GPRS is slow. But if you use the text-based part, and were good with CLI, it was great. I never got to like very small keys, but for me a 'full' qwerty keyboard is a huge upgrade over T9. I never liked nor used T9 much. I avoided it as much as I could. I own a Planet Cosmo Communicator which is a homage to the Nokia Communicator (as well as Palm devices). I also purchased the successor, the Planet Astro Slide, which has a slideout keyboard like the (patented) Nokia N900 (among others, like Symbian-based). The keyboard of these devices is, like the Planet Gemini's, great. That said, I believe a smartphone like Nokia N95 was more of a game changer for the general consumer. And Nokia became popular because of their iconic dumbphones (and their networking pioneering, hence their name reference to town in Finland); not so much their smartphones.