Well that's certainly one route I could go down... mounting to a USB stick looked tricky and involved a lot of that fsck stuff in Single User Mode, I'll have to have a look and see what I can do...
I've a question about mounting disks. It says you can mount a disk to a USB stick - but how? My hard drive is 250Gb, I've got 170Gb ish free or something like that. A USB stick is nowhere near that capacity. Do you mount the entire capacity, storage space-wise to the USB stick? Or is the backup on the USB stick simply an "image" of what's on the drive?