Used in Wordpress functions.php. It searchs the content of the post for a single word after an @ symbol and autolinks it to their twitter profile.

Twitter-Autolink.js

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

add_filter('the_content', 'content_twitter_mention');
add_filter('comment_text', 'content_twitter_mention');