Featured image and rss etc

Hey,im not sure if this is very relevant with the theme,but i thought that you might be able to help.

With the following code in fuctions.php,the featured image appears on rss feed…

function featuredtoRSS($content) {
global $post;
if ( has_post_thumbnail( $post->ID ) ){
$content = '' . get_the_post_thumbnail( $post->ID, 'thumbnail', array( 'style' => 'float:left; margin:0 15px 15px 0;' ) ) . '' . $content;
}
return $content;
}

add_filter('the_excerpt_rss', 'featuredtoRSS');
add_filter('the_content_feed', 'featuredtoRSS');

The problem is that still i cant make the featured image to appear as thumbnail in other people blogrolls etc (no thumbnail tag exists,only title and content).

Alex is there a way to do this?