The cheapest way to backup your data is to use external devices like CD/DVD or USB drives.
Let us consider the features of the external media currently available:

1. CD-ROM Disks: One of the cheapest backup media available, the CD can store about 700 MB of data. One can easily store data on a CD with the help of CD-writers which are common in most computers available today.
2. DVD-ROM Disks: These are a bit costlier than CDs but considering that one DVD disk can store 4.2 GB of data; the cost per GB is less as compared to CD.
3. USB Drive: Falling memory prices have made these backup media very cost effective. The additional advantage of these drives is that they can be reused many times unlike the CD/DVD. The only drawback is that usually a USB drive is required on the computer which may not be present in all computers.

Data backup to any of the above mentioned devices can be done in one of the two ways:

• You can directly copy data from your ‘My Documents’ folder or any other location to the backup media. This manner of making a backup is the simplest method to backup your data. However, when you take frequent backups, this method creates a problem. It becomes very frustrating to identify which copy of the many copies available with you is the correct file that you want. After all, all of the back ups would have the same name and apart from the backup date there is no way to identify the file that you want.
• This problem can be solved by using data backup software. It allows you to schedule unattended backups which take place at the intervals specified by you. There are a number of such software packages available. One of them is Second Copy (www.centered.com). The important thing to look out for is that the backup media should be stored separately from the original computer otherwise it may not be very useful in case of a major catastrophe. Apart from scheduled backups, these backup software have the ability to backup data spanning multiple disks; a feature not available directly.

Backup to other media is definitely better than backing up on tape media because of the fact that tape backups are necessarily sequential in nature. Hence, you need to restore all the files to get a selected file using tape media.
However, the best backup strategy is to combine ‘backup on external media’ with ‘backup to online storage’. The most critical files should be backed up every day online and the complete data can be backed up on CD/DVD every week or so and moved to a secure location. The chances of data loss are very minimal in this backup strategy.