Last year, according to Arthur C Clarke, western civilisation should have been enjoying regular space travel, video payphones and the opportunity to discover an enigmatic monolith on the moon.

The Kurt Russell movie Escape From New York indicated that the mobile phones of the late 1990s would be roughly the size of a pillow. Dick Tracy suggested that we would have wristwatch videophones 40 years ago.

Obviously, predicting the future of technology isn't easy. But now that the humble PC is 21 years old, a number of similarly misguided predictions for personal computing are being made by professional 'futurologists'.

One proposal is a mobile phone embedded into your jawbone. Another, from a futurologist at BT, suggests that chips built directly onto your retina would replace computer monitors.

Considering that the current delay for life-saving heart surgery is about six months to a year, I wonder what the waiting list will be like for a retinal SXGA upgrade.

Back in the 1960s, the BBC's Tomorrow's World programme came up with stuff like this all the time: disposable clothes made of paper, cars that change colour according to your mood, and intelligent houses run by computers.

But think of all the impracticalities. I for one don't relish the idea of having to reboot my home five times a day. Maybe it'll reboot itself whenever you hold down three light switches simultaneously?

Instead, take a look at how little the PC has changed in 21 years. Today's desktop PC is little smaller than IBM's original, and is still dominated by keyboard input.

Sure, notebook computers are a far cry from the hulking Osborne 1, but they're still too expensive to be commonplace. In fact, most attempts at making PCs smaller are rudely derided in the workplace as being domestic toys, a criticism levelled at Apple's iMac series, and the all-in-ones from Hewlett Packard and Acer.

Miniaturisation has its own problems. Look at your wristwatch now. If it was a Dick Tracy videowatch, the angle of your arm and the proximity to your face would force callers to stare up your nostrils in glorious close-up.

To avoid this, you would have to hold the watch in front of your face, looking like Adam Ant did 21 years ago in the Prince Charming video.

If I was futurologist for a day, my prediction for the next 21 years of personal computing would be more of the same: more wireless networking of devices and more integration of handheld products as an adjunct to, not a replacement for, PCs.

Videophones are probably on the way, but they'll be on a screen, not inserted into my internal organs, thank you very much.

Voice control, video recognition and tablet screens must come, otherwise we'll be stuck with keyboards and mice forever. Yet printers will still exist, and so will scanners.

We'll still wear clothes made of fabric, and not all cameras will be digital. There will be no George Jetson rocket cars, and hopefully no Shockwave-embedded toilet paper.

But I could be wrong. It could well be that in 21 years' time videowatches will have made nostril vision as commonplace as text messaging is today.

For the futurologist, ridicule is nothing to be scared of.