I was reading a blog “LiveSide” and came to know that an optimized version of Microsoft Translator is now available for mobiles, though it is still in beta stage.
I visited the URL http://www.microsofttranslator.com/m/ on my Nokia 5800 XpressMusic; and this service seems very handy in many situations like you are learning another language or you want to impress your friend :).
Currently you can translate words and small sentences in thirty (30) languages with autodetection of source language.