I study several foreign languages at the same time and I would like to have a feature of random interface language switching during GUI login. I find it easy and natural to learn languages that way, because I can easily "guess" the meaning of the most of UI menus, labels etc. just by their position in a "fixed" hierarchy.
So the question is, is there an existing implementation of such a feature and, if not, how could one implement it? Is there a single global environment variable that should be changed in order to achieve the desired behaviour of Ubuntu Desktop GUI?