Dynamically load Facebook comments on your site (if you already have the FB API running)

dynamic-facebook-comments.js

jQuery( function( $ ) {
  if ( 'undefined' === typeof FB )
		return;

	if ( $( 'body' ).hasClass( 'single-post' ) || $( 'body' ).hasClass( 'page' ) ) {
		var $comments_div = $( '<div/>' );
		$comments_div.addClass( 'fb-comments' );
		$comments_div.attr( 'data-href', document.location );
		$comments_div.appendTo( $( '.primary-content' ) );

		FB.XFBML.parse();
	}
} );