Try mSpy Phone Tracker for Your Kid's Safety
This is a new app (application) for i-phones that instantly translate any visual text from Spanish to English or the other way round. You can see the official ad here: Word Lens.
Of course, reality is not so cool, fast and accurate as the official ad wants us to believe. In their ad you can see that translations are not 100% correct, but they are always easy to understand. Reality is that the application takes some time to translate and translations sometimes are totally wrong, but still, very useful when you don't know the language at all. Pretty impressive. Especially the way it changes the letters but keeps the background the same!! Check this out.
NOTE: Today (Jan 2014) this app has become part of Google Translate app, and it is much better and faster than when this video was published here (Dec 2010). Have a look: Google Translate.