Check out http://www.microsofttranslator.com/dev/ http://www.microsofttranslator.com/dev/ - I find the translations aren't always as good with idiomatic phrases

Check out http://www.microsofttranslator.com/dev/ http://www.microsofttranslator.com/dev/ - I find the translations aren't always as good with idiomatic phrases, but it does a pretty good job and the API is complete and easy to use.