"Rsync" or "How I Sync My USB Stick With iTunes" :)

rsync -vruW —ignore-existing —delete —size-only —exclude ‘.DS_Store' —delete-excluded —exclude ‘Podcast' Music/iTunes/iTunes\ Music/ /Volumes/USB\ STECK/iTunes\ Music/

What this does is basically synchronize “/Volumes/USB Steck/”; with my “iTunes Music”; Folder. It ignores the “podcast”; directory and also excludes those .DS_Store files