Add a Facebook Like/Fan box to Blogger

I) Get your Facebook page ID URL

1. Visit Facebook and go to your page.
   
2. Copy the Id URL from your browser’s address bar. It’s at the end of the url.  Trim the URL until you get something like this:
   http://www.facebook.com/pages/Blogger-Sentral/115496238467364
   [http://www.facebook.com/pages/PAGE-NAME/PAGE ID]

II) Configure your Like box

1. Go to Facebook Like box configuration page (opens in a new tab/window). You will see a configuration box, like this (Facebook has replaced Facebook Page ID with Facebook Page URL):
   
2. Now paste your page ID URL inside the Facebook Page ID URL text box.
3. Set other parameters such as width, height and stream. The Preview on the right will update itself as you enter the changes.
4. Click Get Code button when done. You’ll be given two codes, titled iframe and XFBML. You only need the iframe code.
5. The iframe code should look more or less like this:

   <iframe src=http://www.facebook.com/plugins/likebox.php?href=http%3A%2F%2Fwww.facebook.com%2Fpages%2FBlogger-Sentral%2F115496238467364&amp;width=292&amp;connections=10&amp;stream=false&amp;header=true&amp;height=280 scrolling="no" frameborder="0" style="border:none; overflow:hidden; width:292px; height:280px;" allowTransparency="true"></iframe>

   Update February 2011:
   It seems Facebook (perhaps erroneously) has the box height fixed to 62px. This allows only your Facebook page title and the Like button to appear inside the box. The faces will be hidden. To show them, you must increase the height. For example, to show two rows of faces, change the height to 280px. There are two heights in the code, make sure you change both.
6. Copy the code (the code provided by Facebook, not the code in no.5).
7. In Blogger, go to Design > Page Elements and click an Add-A-Gadget link. Select HTML/Javascript gadget and paste the code in the content box.
8. Save and view your blog.
9. Enjoy!