If you need to copy a CD to your hard drive:

  prompt@shell$  dd if=/dev/cdrom of=/path/to/cdcopy.iso

For a DVD:

  prompt@shell$  dd if=/dev/dvd of=/path/to/dvdcopy.iso

• Writing ISO Images to CD with cdrecord by staff
• Cross-Platform CD Index by Shawn P. Garbett
• A Five Minute Guide to Opposing DRM by Bruce Byfield