Optical media (CDs and DVDs) are an acceptable solution for secondary backups, since the discs are easily transported offsite--say, left at your office. But unless you have an HD DVD or Blu-ray drive, you're going to need multiple discs for a full backup; CD capacities max out at 700MB and DVDs at 8.5GB. The media is also rated at varying speeds--represented by a number followed by an X, where X equals 150KB/s--and there's no guarantee same-rated speeds from different vendors will perform comparably. Burning can be time-consuming and tedious if you keep a library of backup disks. HD DVD and Blu-ray discs offer much higher capacities. HD DVD discs currently max out at 30GB and Blu-ray discs at 50GB, but TDK recently announced it was developing 100GB discs. Unfortunately, both the drives and the discs are costly. Optical media is a good choice if you want CDs and DVDs you can play on your consumer electronics devices, but we recommend waiting for prices to fall before considering HD DVD or Blu-ray as a backup option.