add_action('admin_head',  'column_admin_head');
function column_admin_head() {
?>
<style type="text/css">.column-column_name { }</style>
<?php
}

if (isset($_COOKIE['visited'])) {
     // cookie set, so it's a returning visitor
     // display page for returning visitors
} else {
     // cookie not set, so let's "tag" this visitor
     setcookie('visited', 1);
     // display page for first time visitors
}

if (!isset($_COOKIE['first_time'])) {
      setcookie('first_time', 1);
     // include popup javascript
     // echo the pop up markup
}  else {
    // subsequent visits will hide the popup
}

//to signify that the user DID an action, we set a cookie with a numerical value of true
setcookie('user_did_an_action', 1);
 
//to verify that the user DID do an action, we check for it's existence
if (isset($_COOKIE['user_did_an_action'])) {
     //do something
}

<?php
 
class RecentNetworkComments extends WP_Widget {
 
	function RecentNetworkComments() {
		parent::WP_Widget(false, $name = 'Recent Comments from this Network');	
	}
 
	function form($instance) {
		$title = esc_attr($instance['title']);
		$limit = esc_attr($instance['limit']);
		$source = esc_attr($instance['source']);
		$content = esc_attr($instance['content']);
		$date = esc_attr($instance['date']);
		?>
			<p><label for="<?php echo $this->get_field_id('title'); ?>">Enter the Widget Title here: <input class="widefat" id="<?php echo $this->get_field_id('title'); ?>" name="<?php echo $this->get_field_name('title'); ?>" type="text" value="<?php echo $title; ?>" /></label></p>
			<p><label for="<?php echo $this->get_field_id('limit'); ?>">
				How many items would you like to display?
				<select id="<?php echo $this->get_field_id('limit'); ?>" name="<?php echo $this->get_field_name('limit'); ?>">
					<option value="2"<?php echo ($limit == 2) ? ' selected': ''; ?>>2</option>
					<option value="3"<?php echo ($limit == 3) ? ' selected': ''; ?>>3</option>
					<option value="4"<?php echo ($limit == 4) ? ' selected': ''; ?>>4</option>
					<option value="5"<?php echo ($limit == 5) ? ' selected': ''; ?>>5</option>
					<option value="6"<?php echo ($limit == 6) ? ' selected': ''; ?>>6</option>
					<option value="7"<?php echo ($limit == 7) ? ' selected': ''; ?>>7</option>
					<option value="8"<?php echo ($limit == 8) ? ' selected': ''; ?>>8</option>
					<option value="9"<?php echo ($limit == 9) ? ' selected': ''; ?>>9</option>
					<option value="10"<?php echo ($limit == 10) ? ' selected': ''; ?>>10</option>
					<option value="15"<?php echo ($limit == 15) ? ' selected': ''; ?>>15</option>
					<option value="20"<?php echo ($limit == 20) ? ' selected': ''; ?>>20</option>
				</select>
			</label></p>
			<p><label for="<?php echo $this->get_field_id('date'); ?>"><input id="<?php echo $this->get_field_id('date'); ?>" name="<?php echo $this->get_field_name('date'); ?>" type="checkbox" value="1" <?php echo ($date == 1) ? 'checked': ''; ?>/> Display Item Date?</label></p>
		<?php 
	}
 
	function update($new_instance, $old_instance) {
		$instance = $old_instance;
		$instance['title'] = strip_tags($new_instance['title']);
		$instance['limit'] = strip_tags($new_instance['limit']);
		$instance['date'] = strip_tags($new_instance['date']);
		return $instance;
	}
 
	function widget($args, $instance) {
		global $wpdb;
		extract($args);
		echo $before_widget;
		echo $before_title;
		echo (@$instance['title']) ? $instance['title']: 'Recent Comments from this Network';
		echo $after_title;
		$limit = (@$instance['limit']) ? $instance['limit']: 5;
		?>
		<ul>
		<?php
 
			$blogs = $wpdb->get_results("SELECT blog_id FROM $wpdb->blogs", ARRAY_A);
			$old = $wpdb->blogid;
			$comments = array();
			foreach ($blogs as $blog) {
				$wpdb->set_blog_id($blog['blog_id']);
				$query = get_comments(array('status' => 'approve',	'number' => 3, 'type' => 'comment'));
				$count = count($query);
				for ($i = 0;$i < $count;$i++) {
					$post = get_post($query[$i]->comment_post_ID);
					$query[$i]->permalink = get_blog_permalink($blog['blog_id'], $post->ID);
					$query[$i]->post_title = $post->post_title;
				}
				$comments = array_merge($comments, $query);
			}
			$wpdb->set_blog_id($old);
 
			function cmp($a, $b) {
				if (strtotime($a->comment_date) == strtotime($b->comment_date)) {
					return 0;
				}
				return (strtotime($a->comment_date) < strtotime($b->comment_date)) ? -1 : 1;
			}
			usort($comments, "cmp");
 
			$comments = array_slice($comments, 0, $limit);
			if ($comments) {
				foreach ($query as $value) {
				?>
				<li>
					<div style="font-size:11px;font-family:arial,sans-serif;">
						<p>
							<em><?php echo $value->comment_content; ?></em> on
							<a href="<?php echo $value->permalink; ?>"><?php echo $value->post_title; ?></a>
						</p>
						<?php if ($instance['date'] == 1) { ?>
						<?php echo date('F j Y', strtotime($value->comment_date)); ?>
						<?php } ?>
					</div>
				</li>
				}
			} else {
		?>
		<li>There are no Comments in this Network</li>
		<?php
			}
		?>
		</ul>
		<?php
		echo $after_widget;
	}
 
}
add_action('widgets_init', create_function('', 'return register_widget("RecentNetworkComments");'));
?>

<?php
add_action('signup_extra_fields','show_extra_fields');
add_filter('wpmu_validate_user_signup', 'check_fields', 10, 3);
add_action('signup_blogform','show_blogform');
 
function show_extra_fields($errors){
?>
<?php if ( $errmsg = $errors->get_error_message('empty_password') ) { ?>
	<p class="error"><?php echo $errmsg ?></p>
<?php } ?>
<p>
<label>Password<br />
<input id="user_name" class="input" type="password" tabindex="20" size="25" value="" name="user_pass"/>
</label>
</p>
<?php if ( $errmsg = $errors->get_error_message('empty_confirm') ) { ?>
	<p class="error"><?php echo $errmsg ?></p>
<?php } ?>
<p>
<label>Confirm Password<br />
<input id="user_name" class="input" type="password" tabindex="20" size="25" value="" name="user_confirm_password"/>
</label>
</p>
<?php if ( $errmsg = $errors->get_error_message('empty_captcha') ) { ?>
	<p class="error"><?php echo $errmsg ?></p>
<?php } ?>
<?php
  require_once('recaptcha/recaptchalib.php');
  $publickey = "YOUR PUBLIC KEY";
  echo recaptcha_get_html($publickey);
}
 
function check_fields($result) {
	if ($_REQUEST['stage'] == 'validate-user-signup') {
		require_once('recaptcha/recaptchalib.php');
		$privatekey = "YOUR PRIVATE KEY";
		$resp = recaptcha_check_answer ($privatekey,
			$_SERVER["REMOTE_ADDR"],
			$_POST["recaptcha_challenge_field"],
			$_POST["recaptcha_response_field"]);
 
		if ($_POST['user_pass'] == '' || $_POST['user_confirm_password'] == '') {
			$result['errors']->add('empty_password', "Please enter your desired Password below");
		}
 
		if ($_POST['user_pass'] != $_POST['user_confirm_password'] || $_POST['user_confirm_password'] == '') {
			$result['errors']->add('empty_confirm', "Please enter your Password again");
		}
 
		if (!$resp->is_valid) {
			$result['errors']->add('empty_captcha', "Please enter the letters you see below");
		}
	}
	return $result;
}
 
function show_blogform($result) {
	$reg = get_option('signup_registration');
	$reg[$_POST['user_email']] = $_POST['user_pass'];
	update_option('signup_registration', $reg);
	return $result;
}
 
?>

...
$reg = get_option('signup_registration');
$password = $reg[$user_email];
unset($reg[$user_email]);
update_option('signup_registration', $reg);
...