The trouble with the expression "virtual office" is that it suggests a nightmarish vision of workers walking around in silver tracksuits with funny head-sets and nowhere to sit.
The reality is quite different, or at least it was at the virtual offices of Andersen Consulting in Paris, a project that has been so successful that Andersen Consulting is gradually adapting the principle for other offices around the world.
Think not of an office, but of a hotel - a specialised hotel, without bedrooms. Instead it has a large number of different types of function rooms.
Andersen moved from theiroffices in La Defense, the 1960s and 1970s tower block complex on the outskirts of Paris, to much smaller premises in a grand building on the corner of the Champs Elysees and Avenue George V, in the city's heart.
You enter into what looks like a hotel foyer, an atrium where workers "check in" at a reception desk. Employees book the space they need by the hour or day: a work-station, a quiet room, a meeting room or whatever. The main floors of the building each have a floor manager making sure people are in the right place at the right time and anything they need is provided.
Everyone carries a smart card which enables them to access messages and routes their telephone calls to the extension they are at.
If a group of people are working together on a project they book the clump of desks for the life of the project.
Personal belongings? You get a drawer in a filing cabinet.
Then there are two other floors with different functions. One is a club floor with a lounge, coffee facilities and so on, but no canteen - on the Champs Elysees, it was pointed out to me, there is no shortage of places to eat. The other is a client floor, at the swanky top of the building, with various function rooms, a roof garden and a gorgeous round room where they throw parties, serve meals or invite people to listen to a string quartet.
Of course, seeing a building is not the same as working there, but I got the impression that most people prefer the new arrangements.
The new offices occupy about 25 per cent less space and are virtual in the sense that there is hardly any paper. The Paris office threw out 150 tonnes of it when they moved. Instead, money is spent on hiring people, often from hotels, whose job it is to make life pleasant. They will fix cars, make hotel bookings, do dry-cleaning and baby-sitting - any of the services that a good hotel would offer.
Near Boston, where Andersen has converted another office along the same lines, the company hired the concierge from the Four Seasons Hotel to make sure that every conceivable "guest" need was catered for.
But of course the hotel is not a model that would work for every type of business: only those where people spend a long time with customers, like consultants or a sales force.
There is another, more familiar model of an office, one which employs even higher technology: the dealing room. The idea here is to cram people into a shed and surround them with lots of technology. The dealing room is the most sophisticated version but others, such as the call centre, are growing even faster.
Call centres - where people handle telephone queries or orders for banks, insurance companies, retailers, travel firms or whatever - are already the fastest-growing single source of employment in North America and seem likely to become the same in Europe. Of course they can be located anywhere. Dial a local number in London for a computer firm and you might be talking to someone in Ireland; dial an airline in the evening and you may find your call answered by someone in the States.
More and more people who would have worked in regular offices find themselves working in these white-collar factories, "manufacturing" services instead of goods.
This divergence of offices into hotels and dealing rooms mirrors a divergence in function. Twenty years ago the offices of a management consultancy and an insurance company would have looked very similar: now the former will become more and more like a hotel, while a larger proportion of the employees of the latter will find themselves in something like a dealing room.
This mirrors the divergent ways in which hitherto similar services are developing. On the one hand there is a growing number of workers who do not work in any one particular place but who need some form of central services and some form of branding to sell their wares. The major accountancy and management consultancy businesses are good examples of this.
On the other hand, more and more people find themselves having to work in service-industry factories: "battery chickens playing computer games", as a stockbroker friend who was taken over at Big Bang put it. Here physical proximity is essential: even people paid vast salaries have to crouch in deeply uncomfortable circumstances because that is the essence of the new factory, the successor to the production line.
There is also a third development in offices: the office in a box. By this I mean the completely transportable office, something you can carry around so that you can work anywhere. The actual work-station could be at home, or in a hotel room, an airline lounge, a car, or maybe the office or home of a customer. Indeed, anyone working in either the hotel or dealing room models will almost inevitably find themselves developing a portable office of some kind.
It is a counterpart to the hotel, because with no personal space you have to be able to carry everything you need around. But it is also a counterpart to the dealing room. Anyone working in one of these white collar factories knows that he or she will not be there for the rest of their days. Self-preservation requires setting up an independent office in readiness for when downsizing strikes. The office in a box, from which one builds up other ventures, is the practical response to job insecurity.
But can people really cram all they need to do their work into something they can carry around? This column is being written on an ancient lap- top, but I would hate not to have the flood of paper on which people send in their work and, in particular, their ideas. Ever tried to read even a 30-page booklet on screen?
But, when pressed, it is amazing how few physical goods people really do need. I am told that when Andersen Consulting moved into its delicious new Paris office, the staff were all issued with little knapsacks. They were not allowed to bring anything from the old office that they could not carry on their backs. Just to make sure they didn't cheat, they were told to make the journey on the Metro.