All and nothing

With Jamendo we use localized urls like www.j.com/en/albums and we handle this detail with regular expressions into an apache rewrites file.

Better or not, this is a way to do exactly the same thing with the ZendFramework programatically.

http://www.gsdesign.ro/blog/using-zend-framework-language-component/

This is maybe heavier because apache rewrites are faster, but you have to instanciate Zend_Translate and Zend_Locale anyway, so when using ZF, it’s a way to remove complexity in the project without loosing performance.