The proliferation of broadband Internet users and devices that can create, store and share data has contributed to a deluge of digital content, the equivalent of 2.4 million times the information in all the books ever written.

IDC Research in its report The Expanding Digital Universe reckons 161 billion gigabytes or 161 exabytes of data was generated in 2006. Its research attempted to account for all the digital documents, photos, videos, emails, web pages, instant messages, phone calls and other digital content cascading around the Internet, assuming an average digital file would be replicated four times.

If it only tracked original data the result would have been a more realistic 40 exabytes, the equivalent of four stacks of books reaching from the Earth to the Sun or all the books ever written multiplied by 2.4 million. YouTube, hosts 100 million video streams a day and experts say more than a billion songs a day are shared over the Internet in MP3 format. The largest category of digital data is email, including spam, and other person-to-person communications which accounted for 1.5 billion gigabytes.

The previous best estimate of the world’s digital data was made by researchers at the University of California, Berkeley, who claimed the globe's information production was 5 exabytes in 2003. IDC estimated there were a billion devices capable of capturing digital images in 2006. Approximately 150 billion images were taken with digital cameras, and another 100 billion with cell phones.

It estimated that the world had 185 exabytes of storage capacity available in 2006 growing to 601 exabytes in 2010. However the amount of data generated is expected to jump to 988 exabytes - close to a zettabyte - by 2010. Fortunately, storage continues to expand in capacity and contract in cost and not all data is stored.

Meanwhile the companies with the unenviable task of keeping up with this deluge are continuing to push the boundaries. In fact the people responsible for the technology that allows us to cram so much data into smaller spaces won the 2007 Nobel peace Prize for their efforts.

France's Albert Fert and Germany's Peter Gruenberg made their nanotechnology breakthrough using electrical response from tiny magnets to impact the way atoms are laid down in ultra thin wafers.  Their giant magnetoresistance (GMR) technology enables laptop computers to squeeze in over 200Gb of data and portable music players to hold more songs and videos.

 Meanwhile the memory card market including Sony, Toshiba, Kingston, SanDisk, Imation and Transcend is now expanding its capabilities to 8Gb and beyond..

While many outlets are still bundling 256Mb memory cards the real entry level is at least 512Mb ($15-$60) but serious Secure Digital (SD) storage for cameras and mobile devices starts at 1Gb ($20-$30). Even 2Gb cards can be obtained for $30-$50, under half the price of 2006.  Meanwhile 8Gb SDHC (high capacity) and 8Gb Compact Flash cards have dropped to $120-$200.

In 2005 you would have paid around $300 for 200Gb external drive, now for the same price you can get 500Gb from mainstream suppliers like Seagate, Western Digital, Maxtor and Hewlett Packard.  External terabyte drives sell for $550-$650.

Even online web service providers, keen to build loyalty, are offering free storage space. Google has boosted its offering to beyond 2.8Gb, Microsoft has upped its free storage limit for Hotmail to 5Gb and Yahoo is offering unlimited storage so images and documents can be access online from anywhere.

Prices continue to trend down across the storage market, and it seems there’s no end to how much can be squeezed into smaller spaces at lower cost.