Google has put automatic language translation software in Gmail. Now Gmail users can rather seamlessly communicate with people who's native tong differs from their own. Gmail will translate their message within the email. That saves you the time of copying and pasting into a different translation service. It may not save much time, but that can start to add up if you do a lot of work with people who communicate with a foreign language.
"I'm proud to announce the integration of Google's automatic translation technology directly into Gmail.
Simply enable "Message Translation" from the Labs tab under Settings, and when you receive an email in a language other than your own, Gmail will help you translate it into a language you can understand. In one click."