Filecalibur
A file manager to sort huge collections of files.
...Using this hash files, differences or modifications of files within this collections are identified and used to modify other collections. It uses rsync to synchronize filecollections with each other.
In the end Filecalibur does nothing what you would not be able to do by hand - but here you can keep track of several tousand files. If you do backups, Filcalibur ensures you that your backups are really identical.