I've been using mondorescue but the cloning use for Remastersys is very interesting. It may have been an oversite but I did notice that an article discussing software for Debian and Debian derived distributions didn't include Debian repository entries along side the ones for the child distribution Ubuntu:

# Remastersys Lenny
deb http://www.geekconnection.org/remastersys/repository debian/

# Remastersys Squeeze
deb http://www.geekconnection.org/remastersys/repository squeeze/