Internationalization and Localization in CakePHP 2.1

I am building a dual language app in CakePHP 2.1.x because of the great reviews of Cake's "built-in" localization features. However, I am wrestling with getting this powerful feature to work.

I know that this topic has been tackled for previous versions of Cake (here, here, here, and here), but it hasn't been solved for Cake 2.x. I am also referencing these articles in the cookbook (yes, I've read the manual):

• http://book.cakephp.org/2.0/en/core-libraries/internationalization-and-localization.html
• http://book.cakephp.org/2.0/en/core-libraries/behaviors/translate.html

Couple of things — I do not want to do separate subdomains for each language. Instead, I prefer URL based language switching with the click of a button (in this case, a flag icon). The site will be actively maintained, so the content needs to update dynamically. Asking the client to maintain two separate sites/databases is out of the question.

I have Translate behavior set up for my PostModel, but I can't tell if it's working. I also initialized I18n by running I18n in the console, have confirmed the database tables exist, have set up my .po files, and have wrapped all my content in __(). However, when I change the default language in my browser to French, the site remains in English.

I've tried the P28n Component, but I think it's outdated for Cake 2.x. I also tried URL-based language switching based on this nuts-and-bolts-of-cakephp article, but apparently it's incompatible with the new CakePHP API.

Can anyone point me in the direction of a tutorial or instructions that work with CakePHP 2.x? One not already referenced here?

Update: I found this article: http://www.localizingjapan.com/blog/2011/11/10/localizing-a-cakephp-application/comment-page-1/#comment-7467. Does anyone know where you place the code for CakeSession::write('Config.language', 'fre'); and setlocale("LC_ALL", "fr_FR.utf8");?