/*
	    Shortcode to display youtube thumbnail on your wordpress blog.
	    Usage:
	    [youtube_thumb id="VIDEO_ID" img="0" align="left"]
	    VIDEO_ID= Youtube video id
	    img=0,1,2 or 3
	    align= left,right,center
	*/
	function wp_youtube_video_thumbnail($atts) {
	     extract(shortcode_atts(array(
	          'id' => '',
	          'img' => '0',
	          'align'=>'left'
	     ), $atts));
	    $align_class='align'.$align;
	    return '<img src="<a href="http://img.youtube.com/vi/'.$id.'/'.$img.'.jpg&quot" rel="nofollow">http://img.youtube.com/vi/'.$id.'/'.$img.'.jpg&quot</a>; alt="" class="'.$align_class.'" />';
	}
	add_shortcode('youtube_thumb', 'wp_youtube_video_thumbnail');



Once done, you can use the shortcode. It accept 3 parameters: The video ID, the image size (0 for 480*360px, 1 for 120*90) and the image alignment.



	[youtube_thumb id="rNWeBVBqo2c" img="0" align="center"]

how to display a thumbnail from a youtube using a shortcode

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