populate a directory tree without the actual files, for example if you want to show someone your hdd content without giving her the data:

on the system with the data, create a list of directories:

find -type d > hdd_dirlist

and a list of files:

find -type f > hdd_filelist

on the target, replay these with

perl -ne'chomp;mkdir$_' ~/hdd_dirlist
touch .empty
perl -ne'chomp;link ".empty",$_' ~/hdd_filelist

beware of the links, if you want to put an actual file in place of a shallow one, rm it first or modify the scripts to create files instead of just links.