I know I’m not the first one to point this out, but I found that the modern smartphone solves (though probably also creates) many of the problems discussed in Donald Norman’s “The Design of Everyday Things”

Would you like a pocket-size device that reminded you of each appointment and daily event? […] It has to be small. It has to be convenient to use. And it has to 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.

The only unmet feature is the “relatively inexpensive” part, but even that is changing.

I know there is still a lot of work to be done, but I’m pretty happy with how many of the problems of task management, password memorization, and number memorization are solved by smartphones.