Two quotes will give you a sense of what it is about:

Like many men, I quickly established a romantic attachment to my G.P.S. I found comfort in her tranquil and slightly Anglophilic voice. I felt warm and safe following her thin blue line. More than once I experienced her mercy, for each of my transgressions would be greeted by nothing worse than a gentle, “Make a U-turn if possible.”

Now, you may wonder if in the process of outsourcing my thinking I am losing my individuality. Not so. My preferences are more narrow and individualistic than ever. It’s merely my autonomy that I’m losing.

The question which comes immediately to mind is the boundary between dangerous dependency and useful tool. Some years ago I had access to a piece of research (but have lost track o f it) which showed that the calculator generation had less sense of the essential rightness or wrongness of an answer that those of us who started with slide rules. I still have mine somewhere and they were wonderful, they took away the drudgery of calculation, but (and it is an important but) you had to be able to work out what power of ten yourself. The calculator generation just get the answer without building that innate sense. Of course any abacus user would wipe the floor with both groups!

I must admit to a view that we should reintroduce slide rules to schools ........