Word Lens, a real time translation app for iOS and Android from QuestVisual, has been acquired by Google. QuestVisual has made the app and the accompanying language packs (which required separate in-app fees) a free download for now.
As Word Lens demo video from its’ launch in 2010 shows, you point your camera phone to any sign and it translates and displays the translated text in the camera feed in real time without any internet connection. It is not perfect, but useful to get the jist of signs and restaurant menus.
Microsoft has a similar free tool called Bing Translator available as a free download for Windows 8.x and Windows Phone.