I’m not sure how or why Janrain seems sneaking in under the radar for easily connecting WordPress website registration and login with social networks, but it is.

Janrain Engage supports 20+ social platforms for registration and login, including Facebook, Google, Twitter, Yahoo!, LinkedIn, PayPal, MySpace, Windows Live and AOL. The solution includes a simple and intuitive user interface that makes it easy for users to sign-in to your site via an existing social network account.

If you’re using a typical WordPress theme, you can use Janrain’s built-in methods to add the login fields above or below your comment box. However, if you’re using Thesis, that method doesn’t work.

Instead, by adding the following small bit of PHP code to your custom_functions.php file you can show the Janrain login buttons in your comment form.

function janrain_login() {
	if ( ! is_user_logged_in() ) {
		echo '<p class="leftie">';
		_e( 'Login with...' , 'custom');
		echo '</p>';
		echo do_shortcode('[[rpxlogin]]');
		echo '<div class="clear"></div>';
	}
}

add_action('thesis_hook_comment_form_top', 'janrain_login');

Once, you’ve added that, now add a bit of CSS to your custom.css file to suit your fancy like so.

.custom #commentform .leftie {
    float: left;
    margin-right: 0.1em;
}
.custom #commentform .rpx_button {
    margin-top: -3px;
}
.custom #commentform .clear {
    clear: both;
}

If you have any troubles, let me know via the comment form.

Ciao!