Google Translate app for iPhone
If you travel all around the world with your iPhone and find yourself in trouble communicating with the locals, Google Translate is the answer for you. Yes, Google Translate is finally available for the iPhone.
The Translate app supports 15 different languages which translates sentences. Plus, 50 different languages to translate words on your device. The app also lets you view dictionary results of the words like the web version of the app, and lets you view recently translated words or sentences when offline. This app is now available in the AppStore, compatible with iOS version 3 or further and only for the iPhone and the iPod Touch.
Source Google Mobile Blog via Phone Arena