Sharp Wizard OZ-7000 (1989)

 It didn't quite fit into a shirt pocket, and its non-QWERTY keyboard wasn't the most intuitive of input devices. But long before the PalmPilot 1000 or even the Newton MessagePad, the first Sharp Wizard helped popularize the concept of a small, lightweight electronic address book and calendar, thereby becoming the granddaddy of the modern personal digital assistant.