(http://i40.tinypic.com/2yjyg3q.jpg)
It's in Microsoft's best interests to get some good quality Windows 8 apps into the Store, and the free Bing Translator tool certainly fits that description.
As well as typing out your queries you can take a webcam shot of signs and documents for instant translations. 40 different languages are supported, including Spanish, French, German and... Klingon. The app also has an offline mode, enabling you to download language packs so you can get quick translations without an internet connection.
Link (http://apps.microsoft.com/windows/en-gb/app/bing-translator/1489bb69-3e78-4085-96f5-2a9a6f303559)