[eluser]JoostV[/eluser]
One way is to set the language in the session. Then you can act on that info, by setting different images, loading a different langauge class, restricting data from teh database to a certain language, and even setting different ways to displayes dates and so on.
If you already have a language detection class, you write a library that:
-checks to see if that language is available
-if it is, set that language in session
-if it is not, set a default language in session , e.g. English
You can then also add language buttons to your site that enable the visitor to choose a different language.