It's not all that long ago - 20 years or so - that most computers were shared, with each user having an access terminal with screen and keyboard. Now a Canadian company called Userful is trying to recreate those days, and it's using the Green bandwagon to do it.

Back then PCs had only just been invented, and they were still too expensive for every office worker to have one - plus of course few people needed enough computing power to warrant having one.

Instead, they could get by quite happily with a monochrome text-only terminal and a share of a super-microcomputer, the latter typically running Unix plus application software specific to the job at hand.

However, PCs are so cheap now that even though you can do the same job more cost-effectively (and more manageably) with thin clients, all too often we say "What the heck, we'll spend a few quid extra and give people the real thing."

Plus the number of applications used by the average office worker has rocketed, as have their expectations, so a monochrome terminal doesn't cut the mustard in most offices these days.

And yet, one thing has not changed - as Userful quite rightly points out, most of us do not need a whole computer to ourselves. The average PC spends most of its time just waiting for the user to press a key, while all the time it is consuming power and producing heat.

So it is promoting its Multi-Station software, which allows you to connect up to ten keyboard/video/mouse combinations to one Linux-based PC, via USB and multiple video cards, as an energy-saving measure. (The extra software enables the operating system keep track of which KVM combo belongs to which user session.)

There are a few issues with this, not least that it has a whiff of 'greenwash' to it, and will only suit those who are already happy to run Linux. Then again, the green and Linux constituencies probably have a fair bit of overlap.

So far, Userful's main successes seem to have been in public libraries and schools - especially in the developing world. It's a nice reminder that useful technology rarely disappears completely, and that just as PCs aren't the solution to everything, neither are thin clients.