I make DUAL backups to ( separate ) CD-R's. I don't want to take a chance on one CD-R getting scratched beyond readability. And, I don't erase the Camera card(s) until the original images are safely archived.
I have a second hard drive also... Every night, i have a scheduled backup that backs up everything in my "My Documents" folder to the second drive. As I get enough material to fill a DVD, I archive the photos.
I use a hardware mirroring (RAID 1) unit with hot swappable drives. While I'm not doing this now, it's something I'm thinking about: get a 3rd drive; every so often (daily/weekly/whatever) pop out the 2nd bay drive, and replace with the extra drive; keep the 2nd bay drive (now the extra drive) somewhere safe. Somewhere safe might be just a 3rd location (kind of like having offsite backup) or a fire safe.
Of course, one has to burn to CD eventually, even it's just for redundancy at times. I try to keep CD burning to a minimum though until I decide to pick up a DVD burner.
