The Research Pane in Word 2007 can help you easily translate text into other languages, using bilingual dictionaries powered by WordLingo.com.

To translate a word or phrase, open your Word document and highlight the text you want to translate. Click the Review tab on the Ribbon and select Translate in the Proofing section. 

The Research task pane will appear.  Choose the language you want to translate to.  If this case I am trying Russian. 

The task pane will display the translation.  If you want to add the translated text you will need to copy and paste it into your document. 

With this tool you can actually translate an entire document. You can also tweak the translation options to suit your individual needs. 

For very large amounts of text, Word sends the document to WorldLingo.com for translation. For instance, here I translated an English document into Japanese (not that I can read it)