InstaDMG

InstaDMG allows for the programmatic creation of Mac OS X deployment images.
InstaDMG creates clean, never-booted ASR images for deploying MacOS X.

It uses Apple's native installers, package formats, and disk image frameworks. The current version is capable of producing 10.5 through 10.8 images while booted from those respective OSs(10.4 should work when built on 10.5, but is not actively tested).