shortcode help require

Here you go:

add_shortcode('latest_tweets', 'latest_tweets');

function latest_tweets($atts){
  extract(shortcode_atts(array(
    'max' => 5
  ), $atts));

  $twitter_id = esc_attr(strip_tags($atts[0]));

  // try to get data from cache to avoid slow page loading or twitter blocking
  if (false === ($output = get_transient("latest_tweets_{$twitter_id}"))):

    $doc = new DOMDocument();
    $feed = "http://twitter.com/statuses/user_timeline/{$twitter_id}.rss";
    $doc->load($feed);

    $output = "<ul>";
    $i = 1;
    foreach ($doc->getElementsByTagName('item') as $node) {
      $tweet = $node->getElementsByTagName('title')->item(0)->nodeValue;
      //if you want to remove the userid before the tweets then uncomment the next line.
      //$tweet = substr($tweet, stripos($tweet, ':') + 1);
      $tweet = preg_replace('@(https?://([-\w\.]+)+(:\d+)?(/([\w/_\.]*(\?\S+)?)?)?)@', '<a href="https://wordpress.stackexchange.com/questions/5663/">$1</a>', $tweet);
      $tweet = preg_replace("/@([0-9a-zA-Z]+)/", "<a href=\"http://twitter.com/$1\">@$1</a>", $tweet);
      $output .= "<li>{$tweet}</li>\n";
      if($i++ >= $max) break;
    }
    $output .= "</ul>\n";
    set_transient("latest_tweets_{$twitter_id}", $output, 60*10); // 10 minute cache
  endif;

  return $output;
}

Usage:

[latest_tweets "DarthVader" max=5]   

PS: you have some exploit in the code you posted in your question. You should take care of that…

PPS: for people who want to do something like this:

• use Yahoo Query Language,
  requests should be faster
  theoretically, and you have less
  chances to be limited by the service
  you’re requesting data from

• use the JSON format for the data you request

• use WP’s HTTP API to make external requests