It's what the French call le nuage informatique and it could revolutionise a lot of stuff. In a sense, we have had the Cloud since the first Hotmail accounts opened and you stored your emails on their servers. That was back in 1996, and you got a measly 2 MB.

Then, in the 2000s, many individuals had experience with Google Documents, or the ever growing storage capacities offered by Yahoo or Google mail. But this is really minor. In the future, big companies could be running their operations entirely in cyberspace, linked to the user via an internet connection, storing amounts of data to be manipulated with online applications in ways that earlier generations could only dream about. The advantages are numerous. Small companies will be especially favoured, according to Cloud optimists.

There are thousands of servers out there with spare computer power, and their computing power can be bought to do company IT work, as much or as little as you need, run on virtual machines created at a moment's notice in data centres around the world. So there is no need to invest in expensive IT structure up front; so start ups, especially starts ups in developing countries, could have a huge barrier to business entry removed.

The difficulty of working with different versions of documents whereby people email working versions to each other will disappear: everyone works on the same document, stored online centrally, so it is no problem wherever you are. The processing power of these spare computers - whether they belong to Google, Amazon, or gaming companies with spare capacity during developed world sleeping hours - can crunch numbers that even hospital IT departments cannot cope with: so more and better radiology diagnoses could take place; better computer aided engineering is another future possibility.
Enthusiasts claim it will flatten the world, and only talent, and ideas, will matter. You could run a company from a laptop.

The British government has talked of creating a G Cloud, the G standing for Government, doing away with the profusion of IT departments and proprietary software, storing all its documents online, so that en employee of the cabinet office will be able to stroll over to the Department of Work and Pensions and access his documents from any terminal there; and it is going hand in hand with the government's push for citizens to do everything online, from filing for VAT, to applying for pensions and benefits. (You can already do your tax return, but you will be able to do so much more.)

And the European Commission is proposing a strategy this spring that will enhance interoperability between different E-Government services in member states. Visit a doctor in Spain and he will be able to read your medical records from the NHS online.

While Microsoft calls the Cloud the potential "Billion Dollar Computer" at every businessman's fingertips, Neelie Kroes, the EU digital agenda commissioner, has pledged that Europe build the world's most advanced system of government services through the internet.

Microsoft, in a recent seminar in Brussels, added that European businesses, facing few venture capital sources, could benefit to a greater extent from the scalable buy-only-what you need services that the cloud offers. Could Albania become the next IT hub? Why not?

But, along with all these upsides, there are downsides too. Integrity of data, privacy, and reliability of service. If your data is stored on servers in hostile countries, who is to say it won't be decrypted, or be vulnerable to cyber spies, whether the health information of millions of Europeans or the latest top secret piece of automotive engineering? Continuity of service is a life or death matter for institutions like hospitals.

So the commission is thinking of stitching together a strategy that will boost the trust EU members have for each other, so that at least this union of 500 million and many data centres can safely share capacity, even if it doesn't rely on the rest of the world.

ENISA, the European Information Security Agency, recently urged national governments and EU institutions to consider the possibility of setting up a 'European Governmental Cloud'. This would be a virtual space where consistent rules could be applied to legislation and security across countries.

The Canadians, after all, have had their spats with their close American allies about Canadian data stored on US servers, showing, perhaps, that the US takes a very strong sovereignty based approach to data.

On the other hand, the recent UK debate about the European Court of Human Rights has highlighted British scepticism about international judicial institutions. The US as a single jurisdiction under common laws will benefit when the Cloud takes off. Will Europeans put aside their differences, and learn to trust each other - can they trust each other? - when taking advantage of a technology that could revolutionise the way we run business?

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Pelle Neroth -- EU correspondent