"hellmachine" posted a one-line terminal command in this MacNN forum which will copy a given directory, including all hidden files and resource forks, to a backup location:
sudo ditto -vR -rsrcFork /Users /Volumes/Backups/UsersThis example would back up the Users directory to a volume named "Backups". The -rsrcFork option will handle the resource fork of the files during the copy.
Mac OS X Hints
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