This contribution is specifically for shipping within the United States and the only language file included is for English.
It should be relatively easy to modify for use in other countries.
This contribution can be used alone, or with the standard zones.php included with osCommerce, with a simple one line modification to zones.php.
When used together, only one or the other will display, based on the country of the shipping address.
Full installation instructions are included in the Readme.txt file.
A support thread has been started at http://forums.oscommerce.com/index.php?showtopic=239938