I am sure you have used Google Translator one time or the other. I am a regular user of the service which I use to translate simple word, phrase, blog article to complete tech documents.
There was always need for checking the translation with someone who is familiar with the language I am translating from. So far it has been over the phone or emails and if the opportunity provides translating together with another person, if one is near by.
Now Google has made it much easier with the new Google Translator Toolkit.
If you chat on GMail, then the Translator Toolkit's chat feature is very familiar to you. You contacts are right there on the left plane and you can buzz someone for help.
But there are more to the Google Translator than the chatting. They have added features like changing the display language and expansion of the dictionary to include additional information like parts of speech and alternate definitions.
Happy Translating and reading!
Official Google Blog: Chat on Translator Toolkit