"We’re always thinking about ways to help you better promote and share your blog content with the world, and the new sharing buttons we’ve just released are great tools to help you get the word out. The buttons—which support sharing via email, Blogger, Google Buzz, Twitter, and Facebook—can be placed under each blog post where your readers will easily see them.

You can turn on the new sharing buttons right now by editing the Blog Posts widget and enabling Show Share Buttons in the Design | Page Elements tab."