http://www.bombich.com/mactips/image.html

carbon copy cloner is good for local disk images and building bootable clones » http://www.bombich.com/software/ccc.html

ditto , asr and psync manage to deal with most of the issues involved in trying to deal with the nonunixish bits of mac files… .

comparison » http://blog.plasticsfuture.org/2006/03/05/the-state-of-backup-and-cloning-tools-under-mac-os-x/