I have a simple model with an attached image using paperclip, which has a couple of processed styles for it (thumbnail, full, feature). At this point
If it is acceptable, you could skip saving the originals, by setting the default style.
has_attached_file :image,
:styles => { :normal => "800x600>" },
:default_style => :normal
If not, and you want to keep the originals, if you are using apache, you could use a .htaccess file to restrict the access to the originals directory
Order allow,deny
Deny from all