I've been following some discussion on kde-i18n on how one can create a really intuitive interface to choose the language. For obvious reasons, this interface cannot depend on any written text. Some have mentioned a large world map where the user would click on her region and this would pick the right language. Unfortunately, this does not work very well since there are many places around where people speak several (and very different) languages in the same region.
Not easy to come up with a universal interface.