Thirty years ago I was a consultant at McKinsey & Company. Computers were in their infancy and many of the companies we saw held the bulk of their information on paper files - rows and rows of them, patrolled by messengers whose sole job was to find files and deliver them around the building. Computers, where there were any, were massive hulking beasts kept down in the basements.

Two great technological achievements have developed hand-in-hand over the intervening three decades. One is the almost ubiquitous availability of personal computers on every desktop. The other is the proliferation of the internet as both a business tool and a means of mass communication.

Personal computers have colonised the office in a way that no one would have dreamed about 20 years ago. Ranks of beige machines dominate, giving an unprecedented degree of autonomy to the people who use them. Through their PCs, workers have become so much more productive, accessing the information and tools they need in seconds. And the recent power cuts in the US and the UK have demonstrated the true extent to which modern workers rely on these anonymous-looking boxes.

As well as bringing autonomy and greater productivity to the workplace, the PC has brought people together outside it. More than two-thirds of households in the US now have a PC with internet access, allowing them to talk to fellow surfers on the other side of the globe.

You only have to look at the blogging phenomenon to see how people love to communicate with one another.

With these advancements, however, come challenges and responsibilities. The speed with which the internet has grown resembles the Wild West of 1850s America, with a general lawlessness that needs to be tackled quickly.

Cross-border legal issues must be resolved, otherwise the prevailing state of anarchy can only deteriorate.

Of course, technology can and does deliver enormous and profound benefits. My company is proud of its work in many diverse sectors, including installing biometric systems at key international airports to ensure the safety and security of air travellers in the wake of the tragic events of 11 September.

EDS solutions are not only improving customer satisfaction by introducing greater efficiency, they are instilling trust and confidence in a world where such commodities appear to be thin on the ground.

On the subject of travel, mobile technology also offers the power of a PC while we're on the move. Where would today's consultants be without their laptops and mobile phones? Yet when I left McKinsey in 1974, these technologies were unknown. We were tied to landlines and office desks. Today's consultants could barely imagine it. And the younger ones certainly couldn't imagine having a social life without mobiles.

Let's not forget, either, how these technologies have improved the lot of developing countries. EDS outsources some of its programming work to India, a trend that will continue.

Highly educated workforces in countries such as India, China and Eastern Europe are attracting impressive volumes of hi- tech outsourcing business, fuelling these nations' economic development. This, in turn, will create new markets in these countries for exports from the developed world, creating a virtual circle of trade and a flow of capital that benefits everyone.

Although the PC has transformed the economic landscape, we are still dealing with the legacy of those enormous room-filling monster computers, and still adjusting to the age of the PC. You can see this in the difficulty we have in swapping information between systems.

Back in my time at McKinsey, companies would have separate systems for their payroll, accounting, invoicing and so on. These different systems grew up independently, without talking to one another. And why should they? There was no need to talk, and engineering them to do so would have required more memory and disk space, which in those days were very expensive.

Now we live in a world where Metcalfe's Law - whereby the usefulness, or utility, of a network equals the square of the number of users - has come into its own. The number of people connected via the internet has exploded in recent years, allowing an unprecedented pooling of knowledge and collaboration.

Communication is the watchword. Yet our office systems still do not talk to one another because they still exist in silos, on incompatible systems written in incompatible computing languages and using incompatible standards.

Looking ahead, the next big task for information engineers and architects is to ensure that the systems of tomorrow - and of the next 30 years - deliver real and lasting benefits to mankind.

Biometrics, smartcards, the internet and technologies yet to be created all have the potential to transform lives, make the world safer and act as a catalyst for change.