This day marks the 1st anniversary of Facebook's LIKE button that can be installed in your website (or blog post)! Try it below:

UPDATE (4/23/2011): For those asking how to place the like button in your blog post, the long answer is here, while the short answer is to copy-paste the following code in the HTML editor of your blog (for Blogger, click the "Edit HTML" in the new/edit post page):

<iframe allowtransparency="true" frameborder="0" scrolling="no" src="http://www.facebook.com/plugins/like.php?href=[replace this with your blog URL]&amp;layout=standard&amp;show_faces=true&amp;width=450&amp;action=like&amp;font&amp;colorscheme=light&amp;height=80" style="border: none; height: 80px; overflow: hidden; width: 450px;"></iframe>

Make sure to replace the value of the href tag with the URL (web address) of your blog post!