Changing The Interface Language of Google Talk

Google Talk is now available in the following interface languages:

Dutch, French, German, Italian, Japanese, Korean, Portuguese, Simplified Chinese, Russian, Spanish, Traditional Chinese, Turkish, UK English, and US English.

To change the interface language of your Google Talk client:

1. Visit www.google.com/talk.
2. Select the appropriate language from the drop-down menu.
3. Click Download Google Talk.

Your Google Talk client will appear in the language of your choice after you complete the installation. You can communicate with your friends in any language, regardless of your interface language.[source]