ImTranslator IE is an excellent plug-in for Internet Explorer that lets you, from the browser itself, translate any text in an amazing number of different languages.
These include Albanian, Arabic, Bulgarian, Catalan, Chinese, Croation, Czech, Danish, Dutch, English, Estonian, Finnish, French, Gallego, German, Greek, Hebrew, Hindi, Hungarian, Indonesian, Italian, Japanese, Korean, Latvian, Lithuanian, Maltese, Norwegian, Philipino, Polish, Portuguese, Rumanian, Russian, Serbian, Slovakian, Slovenian, Spanish, Swedish, Thai, Turkish, Ukranian, Vietnamese, etc.
As if that wasn`t enough, you also have, in ImTranslator Explorer a voice synthesizer, that can read any text in English, German, Chinese, French, Italian, Japanese, Korean, Portuguese, Spanish and Russian.
ImTranslator Explorer is an plug-in that you can classify as totally essential, without any doubt.