Bootable
Next task: make a bootable USB thumb/stick/drive/thing to rescue a busted machine (In this case, little old Brahms). dkg, as ever, knows what's what and gave me great advice: Bootable USB sticks are just like bootable hard drives for modern computers. Partition them with parted, use mkfs to create a filesystem on them, use grub-install to give them a bootloader, put a kernel and an initial ramfs on them, configure the bootloader to load them, and away you go. He even offered me his filesystem rescue debirf image with the latest 686 kernel from debian unstable.