Allow files or folders to be extracted from the normal backup into a separate "offline" backup. The selected files / folders would be completely removed from the backup (except possibly for some sort of note or link in the backup that says it was archived at a certain version). All versions (or maybe selected versions) of the files should be included in the backup (ie: it should be stand alone).

Assuming you deleted the files from your hard disk at the same time, they should reduce the size of your backup.

The archive could be a special sort of Cucku backup database that is marked as an archive. But the file extension could be associated with Cucku to make it easy to open.

The archive could then be saved to DVDs or some other hard disk.