CARS that tell you when to turn left or right moved out of Knight Rider into the real world a while ago.Some of the latest models warn you when you're veering out of lane.

CARS that tell you when to turn left or right moved out of Knight Rider into the real world a while ago.

Some of the latest models warn you when you're veering out of lane. New ones may soon tell you to slow down in speed-limit areas.

Sailors and other navigators no longer need a sextant and compasses to plot their course.

And at the Suffolk Show this week I saw a tractor that can be guided by GPS – global positioning system – to plough a straight furrow or harvest a wheat field efficiently. (Whatever happened to the old farming skills still being celebrated in another, more nostalgic, corner of the showground?)

Is this space-age technology stunningly impressive, rather spooky, or something we should be worried about? A little of all those things, I suppose.

The impressiveness and spookiness should be pretty self-evident. It's not many years since the first four paragraphs above could only have appeared in science fiction.

The reasons for being worried take many forms – including, no doubt, many that haven't been thought of yet.

The over-riding fear is to do with where this mind-bending technology comes from.

If you don't already know, it will not surprise you to learn that it was designed for – and is still controlled by – the United States military.

Not people I would really want in control of my driving, or anything else about the way I lead my life.

Depending on your viewpoint, it is either a spin-off from the "Star Wars" defence system we heard so much about in the Reagan years, or the real reason so much effort was put into that bizarre initiative.

A conspiracy theorist might suppose it is all part of a grand plan for the suits in the Pentagon to control the rest of the world.

In general, I tend towards the cock-up theory of history, though the conspiracy version generally has better stories. In this case, though, the conspiracy theory is believable enough to be taken very seriously by some very serious people.

The European Space Agency may be a (very) little brother to Nasa. But the EU is giving a lot of thought and a lot of dosh to the Galileo programme and its plan to get a European equivalent of GPS up by the middle of next year.

A year-long deadlock between European nations has been broken by the shared fear that the US might use GPS – or withdrawal of its services – as another tool to bully other governments, even "friendly" ones.

Mind you, I'm not really sure if sending dozens more clever satellites into orbit is the best way to shrug off the pervasive power of the Pentagon.

Maybe we should all just learn again how to read maps, plough straight, and take measurements from the sun and the stars. And stay awake at the wheel.