I'm doing something wrong here...
I've managed to change the locale by using the '?_locale=el' http://pyro.chinopoulos.com/demo?_locale=el http://pyro.chinopoulos.com/demo?_locale=en
...but URI hint is not working http://pyro.chinopoulos.com/el/demo http://pyro.chinopoulos.com/en/demo
I am affraid this does not work this way for Pages/Posts modules. maybe Ryan would be of more help here. But this maybe is going to change in next version of pages? :)