"The original IBM 'RAMAC' hard disk had 5MB capacity, weighed about two tons and took up the same space as two conventional refrigerators," says Corne Kruger, IBM product manager at Tarsus Technologies. "Best of all, the 'RAMAC' was available for a monthly rental of $32 000," he chuckles.

Looking at just how dramatic a leap this has been, the increase from 5MB to 750GB (considered to be the largest capacity hard-disk available today) represents an increase of 14m percent, 140 000 times the highest capacity drive available 50 years ago.

"That is nothing short of amazing," he adds. "Considering that Apple has just released an 80GB iPod for the express purpose of listening to music, viewing photos and watching video in a mobile fashion, personal storage is undoubtedly one of the biggest contributors to this phenomenal growth.

"Now add to the capacity of the iPod, the fact that IDC estimates the average hard drive capacity shipped on desktop computers in the past year was 109GB and the fact that this is predicted to rise to 129GB in the next year; there truly seems to be nothing capable of filling the world's capacity for storage space," Kruger adds.

As the old adage goes, necessity is the mother of invention. Kruger says the technological developments made in hard disk technology have not been driven out of pure innovation, but rather from the world user market's appetite for storage.

"If we take a long hard look at where this appetite came from, hard disk storage stems almost directly from the need for a quick and easy storage mechanism for operating systems, office applications and the documents created by them.

"From there, as computer usage increased, applications became more functional and users began doing more with their computers, so the demands in storage slowly crept up. The next big wave happened when computer usage patterns became more personally motivated," he adds.

"This is where the truly explosive appetite for storage stemmed from - today it is not uncommon for a user to house their digital music, photos and video on a single hard disk. Since these sentimental items will always need a storage space, volumes can only rise exponentially," Kruger continues.

Hard disks are also creeping into all forms of consumer electronics. "The iPod is just one example," Kruger says.

"Today PVRs from Multichoice record our television programmes automatically in a digital form - hard disks are used to fuel that storage requirement. The in-flight entertainment systems on intercontinental airlines are no different - content is stored centrally in a hard-disk array and dynamically streamed to passengers' seats on their request.

"While we have no doubt come forward in leaps and bounds as an industry, with aerial densities making it possible for more and more data to be crammed into smaller spaces, I feel that we are only scratching the surface of what is possible.

"Who knows?" Kruger concludes, "in 50 years' time we may be looking back on today, fondly remembering the ridiculously small capacities, alarmingly high prices and large form factors we had to contend with."