Would you like a pocket-size device that reminded you of each appointment and daily event? I would. I am waiting for the day when portable computers become small enough that I can keep one with me at all times. I will definitely put all my burdens upon it. It has to be small. It has to be convenient to use. And it has to be relatively powerful, at least by today’s standards. It has to have a full, standard typewriter keyboard and a reasonably large display. It needs good graphics, because that makes a tremendous difference in usability, and a lot of memory—a huge amount, actually. And it should be easy to hook up to the telephone I need to connect it to my home and laboratory computers. Of course, it should be relatively inexpensive.
– Donald Norman, The Design of Everyday Things