How to mirror a directory structure without the files

Have you ever needed to copy or replicate an entire directory structure without the files themselves?  I’ve often needed to do that when setting up some USB hard drives for offsite replication with ShadowProtects ImageManager.  I found a nice simple way to do it with the Robocopy command

robocopy E:\SPBackup F:\OffsiteBackup /e /xf *.*

That command basically tells it to copy all the directorys in the SPBackup folder over to the OffsiteBackup folder even if they are empty, but to exclude the files themselves.  Works a treat!