Yesterday I did a bunch of research into resurrecting blowed-up disks and found some excellent advice on making a bootable CD with disk utilities for resurrecting/repairing/recovering a drive. Following the directions, I used BootCD to build a disk image with some repair utilities and burn it to CD. I started the machine last night with the CD (BootCD does an excellent job—I highly recommend it), and ran DiskWarrior again, with minimal results—whatever I did to it, this disk is toast. I decided to settle for recovery, and ran Data Rescue X overnight to scan the entire disk thoroughly. This morning, it presented a detailed report of the entire disk and several options for recovery, which is a godsend. We may lose some files, but it looks like the majority (knocking on wood) are still present and accounted for; I just need to get them off the drive and onto a clean disk.
The secondary (newly built) disk I’d copied all the original data onto looks to be in reasonable shape. I threw it in a FireWire enclosure and it popped right up on the desktop of my powerbook, which is is a Good Thing. I’m going to wait until I get my hands on the new iBook with a Superdrive, buy about 50 DVD-R’s, and back the whole thing up manually.