You may as well use CD to backup, but you will either need to dump CD-R discs often, or insert a CD-/+RW discs often to make another backup. Someone else can also misplace your backup CD disc or overwrite your backup data with other information. Moreover, a CD only admits about 700Mb of data, which may not be convenient. Nor is storing multiple CDs of your backup copy.The same can be said about backing up to DVD. Of course, a DVD admits from 4.7Gb to about 18.6Gb of data, but is it really convenient backing up to DVD? An external hard disk drive or a flash USB drive will be speedier, more reliable and easier overall.

Here is when a flash USB drive comes handy. It not only allows faster data copying than CD or DVD, but can also admit from 256Mb to 4Gb of data (or maybe more). Moreover, you can take the USB drive with you anywhere you go and transfer the data between distant computers without resolving to FTP backup. Of course, one of the drawbacks of a flash USB backup is that the drive is only limited to about 100 000 writings, while another slight disadvantage (or an advantage, if you put it nicely) is that the device is so small you can easily misplace it.