English speakers living in countries where the native language is something else often wish to have their System Preferences/Language & Text/Formats/Region set to a mixed value, such as "Italian (English)." While this is normally possible when you first set up your OS, such a setting will disappear if you switch it to something else, so you cannot get it back directly.
In such a case, try opening Terminal.app and inputting the command
defaults write ~/Library/Preferences/.GlobalPreferences AppleLocale en_IT
Of course you will need to change the IT for Italian to whatever country you are aiming for.