One of the many growing requirements that I am experiencing at work is for internalization of our forms. In this particular use case the languages available are limited to English and Spanish so I am not able to use Zend_Locale::BROWSER exclusively. To make sure that correct form displays, in my form model class I created an array of allowed locales. Before the form instantiated in the controller the language param is set the registry, and then that locale is checked against allowed locales.References:
Translations - located in my models directory: Models/Languages/En.php and Es.php
If locale is allowed then the form label translation is set.