Babelizer is a toy that humorously exposes the inadequacy of machine translation. You type in a phrase, choose a language, and the Babelizer uses the Altavista translation web site to translate between English and your chosen language until the result no longer mutates.
One World Dictionary by Ascendo is a leading multilingual reference tool for Apple desktops.
InstantTranslate makes it really easy to translate a selection of text in the application you are working in from one language to another language.
