Over the past few years we have all seen our hard disks grow to enormous capacities and various other media, such as Iomega's Zip drive, take off as a means of backing up mass storage.
More recently, however, an alternative solution has become possible - writing your own CD-Roms. Not long ago, it would have cost thousands of dollars to buy a device to create your own CD-Roms.
Now they are getting cheaper - Sony has produced one that is just over $2,000. At that price, I cannot imagine anyone seriously considering any other medium.
A CD-Rom is about as permanent a medium as can be created at the moment. They are not, of course, truly permanent, but they are considerably more stable than any other medium about.
The other great advantage of the CD-Rom recorder is that the product - a CD-Rom - is readable by everybody.
I have had numerous conversations with people about transferring large files - 100 megabytes or more - only to discover that I have a Jaz drive but he has a Zip, or some other device that I had not bothered to run out and buy the moment it went on the market.