This looks like a great OSX utility:
Carbon Copy Cloner (CCC) is a cloning utility developed with AppleScript Studio. The purpose of CCC is to assist you in copying your entire Mac OS X installation from one partition to another as easily as possible. Contrary to some misinformation, it is possible to clone your startup volume without Disk Warrior, Retrospect, or any commercial product — the tools you need are already installed with Mac OS X! CCC puts a friendly interface on these tools to make cloning easy.
