Multi language application

[eluser]Stoppy[/eluser]
Hi!
I have to develop a multi language application. What is the best way to do it in codeigniter?

Consider I am going to use datamapper and that I would like just to do it changing language files according by the url the user is visiting.

example:

www.mysite.ext/mycontroller/
www.mysite.ext/mycontroller/mymethod/url_rewriter.html

www.mysite.ext/es/mycontroller/
www.mysite.ext/es/mycontroller/mymethod/url_rewriter.html

www.mysite.ext/fr/mycontroller/
www.mysite.ext/fr/mycontroller/mymethod/url_rewriter.html

and so on....

Thank You!