diff -upN drupal-6.0-beta3/modules/system/system.admin.inc drupal/modules/system/system.admin.inc
--- drupal-6.0-beta3/modules/system/system.admin.inc	2007-11-16 14:16:50.000000000 +0100
+++ drupal/modules/system/system.admin.inc	2007-12-05 17:26:22.000000000 +0100
@@ -604,6 +604,7 @@ function system_modules($form_state = ar
     $form['name'][$filename] = array('#value' => $file->info['name']);
     $form['version'][$filename] = array('#value' => $file->info['version']);
     $form['description'][$filename] = array('#value' => t($file->info['description']));
+    $form['memory'][$filename] = array('#value' => $file->info['memory']);
     $options[$filename] = '';
     // Ensure this module is compatible with this version of core and php.
     if (_system_is_incompatible($incompatible_core, $files, $file) || _system_is_incompatible($incompatible_php, $files, $file)) {
@@ -1907,6 +1908,7 @@ function theme_system_modules($form) {
   $header[] = t('Name');
   $header[] = t('Version');
   $header[] = t('Description');
+  $header[] = t('Memory usage');
 
   // Pull package information from module list and start grouping modules.
   $modules = $form['validation_modules']['#value'];
@@ -1949,6 +1951,7 @@ function theme_system_modules($form) {
       $row[] = '<strong>'. drupal_render($form['name'][$key]) .'</strong>';
       $row[] = drupal_render($form['version'][$key]);
       $row[] = array('data' => $description, 'class' => 'description');
+      $row[] = drupal_render($form['memory'][$key]);
       $rows[] = $row;
     }
     $fieldset = array(
diff -upN drupal-6.0-beta3/modules/system/system.module drupal/modules/system/system.module
--- drupal-6.0-beta3/modules/system/system.module	2007-11-21 23:33:30.000000000 +0100
+++ drupal/modules/system/system.module	2007-12-05 17:52:24.000000000 +0100
@@ -49,6 +49,7 @@ function system_help($path, $arg) {
       }
       $output .= '</p>';
       $output .= t('<p>It is important that <a href="@update-php">update.php</a> is run every time a module is updated to a newer version.</p><p>You can find all administration tasks belonging to a particular module on the <a href="@by-module">administration by module page</a>.</p>', array('@update-php' => $base_url .'/update.php', '@by-module' => url('admin/by-module')));
+      $output .= rate_memory();
       return $output;
     case 'admin/build/modules/uninstall':
       return '<p>'. t('The uninstall process removes all data related to a module. To uninstall a module, you must first disable it. Not all modules support this feature.') .'</p>';
@@ -1698,3 +1699,19 @@ function theme_system_powered_by($image_
   $image = theme('image', $image_path, t('Powered by Drupal, an open source content management system'), t('Powered by Drupal, an open source content management system'));
   return l($image, 'http://drupal.org', array('html' => TRUE, 'absolute' => TRUE, 'external' => TRUE));
 }
+
+function rate_memory() {
+  $mem_in_use = round(memory_get_usage()/1024/1024, 2);
+  $mem_limit = intval(ini_get('memory_limit'));
+  $mem_avail = $mem_limit - $mem_in_use;
+  if ($mem_avail < 5) {
+    $class = "messages error";
+    $help  = "<br>You have too less memory. Please disable some modules or raise your memory limit.";
+  } else {
+    $class = "messages status";
+    $help  = "";
+  }
+  $output = t('<div class="@class">Memory usage: @mem_in_use of @mem_limit MB.', array('@class' => $class, '@mem_in_use' => $mem_in_use, '@mem_limit' => $mem_limit)) . $help . '</div>';
+  
+  return $output;
+}
\ No newline at end of file