Best way to backup large, trashed partition to CD

[Ross Boylan <RossBoylan@stanfordalumni.org>]

I have a large partition that is damaged, and so currently unreadable.
I would like to back it up in case I ever feel like trying to
reconstruct it, and then get rid of it.  My backup is CD-R. 

I said dd if=/dev/hdxx of=bigImage
and then bzipped bigImage.  However, the result is still larger than a
CD can hold.

What's the best way (or even a way) to handle this?

Thanks.