Why don't you declare your variables inside a module with the variable module. Then you could use and translated them.
I suggest you read this: http://www.lullabot.com/blog/article/module-monday-variable
I don't think there is a way of having things translated in drupal without using the database, so i give you a simple option of using variable module as the only way.
you can add in your module.info file, so it will work as you enable your module.
/**
* Implements hook_install().
*/
function mymo_install() {
// save the translation of your variable
variable_store_set('language', 'es', 'site_name', 'Este es mi Sitio', TRUE);
}
you could delete things with hook_uninstall if you want.
hope i don't get extra -1, it helped!could be useful to someone else...