1. In the file "comments.php" of the theme you're going to use, find:

<?php wp_list_comments(); ?>

And replace with:

<?php wp_list_comments( array('callback' => ( function_exists('twitter_comment') ? 'twitter_comment' : null ), 'avatar_size' => 96 ) ); ?>

2. In the same file (comments.php) of the theme you're going to use, find:


<?php else : ?>

<p><input type="text" name="author" id="author" value="<?php echo esc_attr($comment_author); ?>" size="22" tabindex="1" <?php if ($req) echo "aria-required='true'"; ?> />
<label for="author"><small>Name <?php if ($req) echo "(required)"; ?></small></label></p>

<p><input type="text" name="email" id="email" value="<?php echo esc_attr($comment_author_email); ?>" size="22" tabindex="2" <?php if ($req) echo "aria-required='true'"; ?> />
<label for="email"><small>Mail (will not be published) <?php if ($req) echo "(required)"; ?></small></label></p>

<p><input type="text" name="url" id="url" value="<?php echo esc_attr($comment_author_url); ?>" size="22" tabindex="3" />
<label for="url"><small>Website</small></label></p>

<?php endif; ?>


And immediately below, add:


<p><input type="text" name="author_twitter" id="author_twitter" value="<?php echo (isset($_COOKIE['author_twitter' . COOKIEHASH]) ? $_COOKIE['author_twitter' . COOKIEHASH] : '' );?>" size="15" tabindex="4" />
<label for="url"><small>Twitter Username</small></label></p>