CD/R disks for backup?

[Bill White <bill.white@griggsinst.com>]

Does anyone use CD/R disks for backup?  I have some questions.
1.) How do you make sure that mkisofs doesn't make a file system which is
    bigger than the disk?
2.) If your partition is 1000Mb and it is mostly full, you have to 
    partition the partition.  How do you do that without much manual
    intervention?
3.) How do you do incrementals?  That is, how do you tell mkisofs to only
    include files which have been changed since a given date?
4.) Is there a convenient way to record system metadata, like the partion
    table contents, so that you could (a) boot from your last level 0 backup,
    and (b) be prompted to repartition your disk?  You might use this for
    a painless mechanism for catastrophic hardware recovery.

I've actually thought about this at some length, and I have some ideas.
I don't want to spam the list with my plaintive bleatings, so perhaps, 
if anyone else is interested, we could continue a more lengthy discussion
via private email.