Facebook has launched a mobile version of its comments box social plugin, which websites and blogs can use to let people comment using their Facebook profiles.

One of the cool things about the comments box plugin itself is that it threads the conversation through your blog as well as the user’s Facebook wall.

“The Comments Box for mobile is the latest update to the plugin to make commenting more social and authentic, improve the quality of conversations online, and drive traffic and engagement to media sites,” Facebook said in a blog post. “For example, in December we added a Subscribe link in the plugin next to the names of people who’ve turned on Subscribe to help them grow their Subscriber base. You can learn more about adding the Comments Box to your site, and best practices for implementation here.”

“We’re continuing to see media sites of all sizes add the Comments Box, including the York Daily Record (York, PA), The USA Today Science Fair blog, and Gannett sites such as The Statesman Journal (Salem, OR), Burlington Free Press (Burlington, VT), and Detroit Free Press,” the company said.

They’re making things pretty easy for those publications looking to implement it on their mobile sites. If you use the plugin on the desktop version of your site, it will automatically appear on the mobile version of your site as well. It doesn’t get much simpler than that.