Auto Template Switcher for Facebook - repost

We want to have the possibility to integrate a joomla website within a facebook page, like we can do with a mobile phone. This tool must allows to automatically switch to a different template when website is seen from facebook page or a mobile phone like iPhone or other. For all other users using standard browsers (e.g. Mozilla, IE, Safari), they will see your default template. In fact what we want is an extension that can integrate a Joomla website that "knows" is website is being accessed from a standart browser, a mobile phone or facebook. Facebook is more important for us now !