Verlinkt automatisch alle Twitter-Usernamen im Inhalt und auch im Excerpt, sowie den Kommentaren.<

gistfile1.php

<?php

function tweetlink($content) {
	$tweetlink = preg_replace('/([^a-zA-Z0-9-_&])@([0-9a-zA-Z_]+)/',"$1<a href=\"http://twitter.com/$2\" target=\"_blank\" rel=\"nofollow\">@$2</a>",$content);
	return $tweetlink;
}

// The content
add_filter('the_content', 'tweetlink');   

// Comments
add_filter('comment_text', 'tweetlink');

// Excerpt
add_filter('the_excerpt', 'tweetlink');