With the Google Translate gadget, visitors to your blog can select their preferred language from the drop-down menu, and using Google’s free translation service, it will display your posts in any of the 50+ languages Google Translate supports.
I have added the gadget to my blog and from my STATS, I could see many of my readers making use of it.
How To Add Google Translate Gadget To Blogger Blog
To add the gadget to your blog, click “Add a Gadget” from the “Layout” tab, and select “Translate” from the list of gadgets under “Basics“.
Save and view your blog. You should now see the gadget on your blog.
Source: Blogger Buzz