Hello,
Not totally new to Linux flavors, and toyed with a few variants of Knoppix, but...

I like the "safety" of a live CD but the speed of HD access. The new unionfs is great. Is it possible to copy an image of the Live CD into a read-only partition and tell any boot loader to look for the CD image there? I'm thinking of two partitions-one for the safe files, one for the usual saved configuratiion and programs I'm "testing" but don't want them to affect my "happy with it" version. Does this make sense?

And I know USB is faster, but I dont want a dongle dangling where it can get damaged. Maybe just mounting an iso image is possible, but I'd like the guarantee that any old crap that I happen to be messing things up with invariably has ZERO access to my "happy with it " image/partition/CD.

Hope it makes sense and I'm not missing something obvious...

thanks