Looks like a good way, I had never seen it before like this.
Code:
SetEnvIfNoCase Referer "^http://www..com/" locally_linked=1
SetEnvIfNoCase Referer "^http://www..com$" locally_linked=1
SetEnvIfNoCase Referer "^http://.com/" locally_linked=1
SetEnvIfNoCase Referer "^http://.com$" locally_linked=1
SetEnvIfNoCase Referer "^$" locally_linked=1
<FilesMatch "\.(avi|wmv|mpe?g|gif|png|jpe?g)$">
Order Allow,Deny
Allow from env=locally_linked
</FilesMatch>