Knoppix offers several options. I've backed up and restored complete installations using dd as discussed in this thread:
http://www.dslreports.com/forum/remark,3882627 This gives you a lot of flexibility. I was able to backup a laptop image of Slackware off onto another box and restore it to a dual boot drive, replacing the previous Red Hat install.
Alternatively, Knoppix includes a program called Partimage. I've not used it, but here's a thread by someone who did:
http://www.linuxquestions.org/questions/history/161771
Hope those get you started.