A class to import a Twitter feed as a WordPress widget

widgets.php

<?php

class RD_Twitter_Widget extends WP_Widget {

    function __construct() {
        /* Widget settings. */
        $widget_ops = array('username' => 'Your username here', 'limit' => 4, 'show_retweets' => true, 'description' => 'A widget to show your latest tweets');

        /* Widget control settings. */
        $control_ops = array('width' => 300, 'height' => 350, 'id_base' => 'twitter-widget');

        /* Create the widget. */
        parent::__construct('twitter-widget', 'RD Twitter Widget', $widget_ops, $control_ops);
    }

    function widget($args, $instance) {
        extract($args);
        /* User-selected settings. */
        $title = apply_filters('widget_title', $instance['title']);
        $username = $instance['username'];
        $limit = $instance['limit'];
        $show_retweets = $instance['show_retweets'];

        /* Before widget (defined by themes). */
        echo $before_widget;

        /* Title of widget (before and after defined by themes). */
        if ($title) {
            echo $before_title . $title . $after_title;
        }
        ?>

        <ol class="tweets">
            <?php
            $doc = new DOMDocument();
            if (($transient = get_transient('RD_Twitter_feed')) === false) {
                $feedURL = 'http://api.twitter.com/1/statuses/user_timeline.rss?screen_name=' . $username;                
                $doc->load($feedURL);
                set_transient('RD_Twitter_feed', $doc->saveXML(), 60);
            }
            else {
                $doc->loadXML($transient);
            }

            $format = get_option('date_format') . ' ' . get_option('time_format');


            $arrFeeds = array();
            foreach ($doc->getElementsByTagName('item') as $node) {
                $itemRSS = array(
                    'tweet_title' => $node->getElementsByTagName('title')->item(0)->nodeValue,
                    'tweet_date' => date($format, strtotime($node->getElementsByTagName('pubDate')->item(0)->nodeValue)),
                    'tweet_link' => $node->getElementsByTagName('link')->item(0)->nodeValue
                );
                if ($show_retweets == true || strrpos($itemRSS['tweet_title'], 'RT ') == false) {
                    array_push($arrFeeds, $itemRSS);
                }
            }
            for ($x = 0; $x < $limit; $x++) {
                $tweet_title = str_replace($username . ': ', '', $arrFeeds[$x]['tweet_title']);
                $str = ereg_replace("[[:alpha:]]+://[^<>[:space:]]+[[:alnum:]/]", "<a href=\"\\0\">\\0</a>", $tweet_title);
                $pattern = '/[#|@][^\s]*/';
                preg_match_all($pattern, $str, $matches);

                foreach ($matches[0] as $keyword) {
                    $keyword = str_replace(")", "", $keyword);
                    $link = str_replace("#", "#", $keyword);
                    $link = str_replace("@", "", $keyword);
                    if (strstr($keyword, "@")) {
                        $search = "<a href=\"http://twitter.com/$link\">$keyword</a>";
                    }
                    else {
                        $link = urlencode($link);
                        $search = "<a href=\"http://twitter.com/#search?q=$link\" class=\"grey\">$keyword</a>";
                    }
                    $str = str_replace($keyword, $search, $str);
                }
                ?>

                <li>
                    <p class="tweet"><?php echo $str ?></p>
                    <p class="published">- <a href="<?php echo $arrFeeds[$x]['tweet_link']; ?>"><?php echo $arrFeeds[$x]['tweet_date']; ?></a></p>
                </li>

            <?php
        }
        ?>

        </ul>

        <?php echo $after_widget; ?>
        <?php
    }

    function update($new_instance, $old_instance) {
        $instance = $old_instance;

        /* Strip tags (if needed) and update the widget settings. */
        $instance['title'] = strip_tags($new_instance['title']);
        $instance['username'] = strip_tags($new_instance['username']);
        $instance['limit'] = $new_instance['limit'];
        $instance['show_retweets'] = $new_instance['show_retweets'];
        return $instance;
    }

    function form($instance) {

        /* Set up some default widget settings. */
        $defaults = array('title' => 'Latest Tweets', 'username' => 'Example', 'limit' => 5, 'show_retweets' => true);
        $instance = wp_parse_args((array) $instance, $defaults);
        ?>
        <p>
            <label for="<?php echo $this->get_field_id('title'); ?>">Title:</label>
            <input id="<?php echo $this->get_field_id('title'); ?>" name="<?php echo $this->get_field_name('title'); ?>" value="<?php echo $instance['title']; ?>" style="width:100%;" />
        </p>

        <p>
            <label for="<?php echo $this->get_field_id('username'); ?>">Your Twitter Username:</label>
            <input id="<?php echo $this->get_field_id('username'); ?>" name="<?php echo $this->get_field_name('username'); ?>" value="<?php echo $instance['username']; ?>" style="width:100%;" />
        </p>
        <p>
            <label for="<?php echo $this->get_field_id('limit'); ?>">Number of Tweets to show:</label>
            <input id="<?php echo $this->get_field_id('limit'); ?>" name="<?php echo $this->get_field_name('limit'); ?>" value="<?php echo $instance['limit']; ?>" />
        </p>
        <p>
            <input class="checkbox" type="checkbox" <?php checked($instance['show_retweets'], true); ?> id="<?php echo $this->get_field_id('show_retweets'); ?>" name="<?php echo $this->get_field_name('show_retweets'); ?>" />
            <label for="<?php echo $this->get_field_id('show_retweets'); ?>">Include retweets?</label>
        </p>
        <?php
    }

}