diff --git flag.inc flag.inc
index 1eb474b..39728c6 100644
--- flag.inc
+++ flag.inc
@@ -6,6 +6,8 @@
  * of Views 2.
  */
 
+include_once dirname(__FILE__) . '/includes/flag.entity.inc';
+
 /**
  * Implements hook_flag_definitions().
  *
@@ -522,11 +524,15 @@ class flag_flag {
    *   The user on whose behalf to flag. Leave empty for the current user.
    * @param $skip_permission_check
    *   Flag the item even if the $account user don't have permission to do so.
+   * @param $flagging
+   *   Optional. This method works in tandem with Drupal's Field subsystem.
+   *   Pass in a flagging entity if you want operate on it as well.
+   *
    * @return
    *   FALSE if some error occured (e.g., user has no permission, flag isn't
    *   applicable to the item, etc.), TRUE otherwise.
    */
-  function flag($action, $content_id, $account = NULL, $skip_permission_check = FALSE) {
+  function flag($action, $content_id, $account = NULL, $skip_permission_check = FALSE, $flagging = NULL) {
     if (!isset($account)) {
       $account = $GLOBALS['user'];
     }
@@ -567,15 +573,25 @@ class flag_flag {
       }
     }
 
+    // @todo: Discuss: Should we call field_attach_validate()? None of the
+    // entities in core does this (fields entered through forms are already
+    // validated).
+    //
+    // @todo: Discuss: Core wraps everything in a try { }, should we?
+
     // Perform the flagging or unflagging of this flag.
-    $flagged = $this->_is_flagged($content_id, $uid, $sid);
+    $existing_fcid = $this->_is_flagged($content_id, $uid, $sid);
+    $flagged = (bool) $existing_fcid;
     if ($action == 'unflag') {
       if ($this->uses_anonymous_cookies()) {
         $this->_unflag_anonymous($content_id);
       }
       if ($flagged) {
-        $fcid = $this->_unflag($content_id, $uid, $sid);
-        module_invoke_all('flag', 'unflag', $this, $content_id, $account, $fcid);
+        // Note the order: We delete the entity before calling _unflag() to
+        // delete the {flag_content} record.
+        $this->_delete_flagging($existing_fcid);
+        $this->_unflag($content_id, $uid, $sid);
+        module_invoke_all('flag', 'unflag', $this, $content_id, $account, $existing_fcid);
       }
     }
     elseif ($action == 'flag') {
@@ -584,14 +600,74 @@ class flag_flag {
       }
       if (!$flagged) {
         $fcid = $this->_flag($content_id, $uid, $sid);
+        // We're writing out a flagging entity even when we aren't passed one
+        // (e.g., when flagging via JavaScript toggle links); in this case
+        // Field API will assign the fields their default values.
+        $this->_insert_flagging($flagging, $content_id, $fcid);
         module_invoke_all('flag', 'flag', $this, $content_id, $account, $fcid);
       }
+      else {
+        // Nothing to do. Item is already flagged.
+        //
+        // Except in the case a $flagging object is passed in: in this case
+        // we're, for example, arriving from an editing form and need to update
+        // the entity.
+        if ($flagging) {
+          $this->_update_flagging($flagging);
+        }
+      }
     }
 
     return TRUE;
   }
 
   /**
+   * The entity CRUD methods _{insert,update,delete}_flagging() are for private
+   * use by the flag() method.
+   *
+   * The reason programmers should not call them directly is because a flagging
+   * operation is also accompanied by some bookkeeping (calling hooks, updating
+   * counters) or access control. These tasks are handled by the flag() method.
+   */
+  private function _insert_flagging($flagging, $content_id, $fcid) {
+    if (!$flagging) {
+      // Create a flagging entity if none was passed in.
+      $flagging = $this->new_flagging($content_id);
+    }
+    $flagging->fcid = $fcid;
+    field_attach_presave('flagging', $flagging);
+    field_attach_insert('flagging', $flagging);
+  }
+  private function _update_flagging($flagging) {
+    field_attach_presave('flagging', $flagging);
+    field_attach_update('flagging', $flagging);
+    // Update the cache.
+    flagging_load($flagging->fcid, TRUE);
+  }
+  private function _delete_flagging($fcid) {
+    if (($flagging = flagging_load($fcid))) {
+      field_attach_delete('flagging', $flagging);
+      // Remove from the cache.
+      flagging_load($fcid, TRUE);
+    }
+  }
+
+  /**
+   * Helper: Constructs a new, empty flagging entity object.
+   *
+   * The returned object has at least the 'flag_name' property set, which
+   * enables Field API to figure out the bundle, but it's your responsibility
+   * to eventually populate 'content_id' and 'fcid'.
+   */
+  function new_flagging($content_id = NULL) {
+    return (object) array(
+      'fcid' => NULL,
+      'flag_name' => $this->name,
+      'content_id' => $content_id,
+    );
+  }
+
+  /**
    * Determines if a certain user has flagged this content.
    *
    * Thanks to using a cache, inquiring several different flags about the same
@@ -631,6 +707,15 @@ class flag_flag {
   }
 
   /**
+   * Similar to is_flagged() excepts it returns the flagging entity.
+   */
+  function get_flagging($content_id, $uid = NULL, $sid = NULL) {
+    if (($record = $this->get_flagging_record($content_id, $uid, $sid))) {
+      return flagging_load($record->fcid);
+    }
+  }
+
+  /**
    * Determines if a certain user has flagged this content.
    *
    * You probably shouldn't call this raw private method: call the
@@ -826,6 +911,11 @@ class flag_flag {
    * token contexts they understand.
    */
   function replace_tokens($label, $contexts, $options, $content_id) {
+    if (strpos($label , 'flagging:') !== FALSE) {
+      if (($flagging = $this->get_flagging($content_id))) {
+        $contexts['flagging'] = $flagging;
+      }
+    }
     return token_replace($label, $contexts, $options);
   }
 
@@ -837,7 +927,7 @@ class flag_flag {
    * Derived classes should override this.
    */
   function get_labels_token_types() {
-    return array();
+    return array('flagging');
   }
 
   /**
@@ -1312,9 +1402,9 @@ class flag_node extends flag_flag {
     return FALSE;
   }
 
-  function flag($action, $content_id, $account = NULL, $skip_permission_check = FALSE) {
+  function flag($action, $content_id, $account = NULL, $skip_permission_check = FALSE, $flagging = NULL) {
     $content_id = $this->get_translation_id($content_id);
-    return parent::flag($action, $content_id, $account, $skip_permission_check);
+    return parent::flag($action, $content_id, $account, $skip_permission_check, $flagging);
   }
 
   // Instead of overriding is_flagged() we override get_flagging_record(),
diff --git flag.info flag.info
index 62511b5..5a8a58b 100644
--- flag.info
+++ flag.info
@@ -6,6 +6,7 @@ configure = admin/structure/flags
 
 ; Files that contain classes.
 files[] = flag.inc
+files[] = includes/flag.entity.inc
 files[] = includes/flag.rules.inc
 files[] = includes/flag_handler_argument_content_id.inc
 files[] = includes/flag_handler_field_ops.inc
diff --git flag.module flag.module
index a4a9fdf..ad74b6c 100644
--- flag.module
+++ flag.module
@@ -169,6 +169,16 @@ function flag_help($path, $arg) {
     case FLAG_ADMIN_PATH:
       $output = '<p>' . t('This page lists all the <em>flags</em> that are currently defined on this system.') . '</p>';
       return $output;
+    case FLAG_ADMIN_PATH . '/manage/%/fields':
+      $output  = '<p>' . t('Flags can have fields added to them. For example, a "Spam" flag could have a <em>Reason</em> field where a user could type in why he believes the item flagged is spam. A "Bookmarks" flag could have a <em>Folder</em> field into which a user could arrange her bookmarks.') . '</p>';
+      $output .= '<p>' . t('On this page you can add fields to flags, delete them, and otherwise manage them.') . '</p>';
+      $output .= '<p>';
+      $output .=   t('You will also want to pick the <a href="@form-link-type-url">"Form" link type</a> for your flag, or else users won\'t have a means to enter values for the fields. (In case a form isn\'t used, the fields are assigned their default values.)', array('@form-link-type-url' => url('admin/structure/flags/manage/' . $arg[4], array('fragment' => 'edit-link-type'))));
+      if (!module_exists('flag_form')) {
+        $output .= ' <strong>' . t("Note: You don't have the <em>Flag Form</em> module enabled. You'll have to <a href='@enable-url'>enable it</a> to have the \"Form\" link-type.", array('@enable-url' => url('admin/modules'))) . '</strong>';
+      }
+      $output .= '</p>';
+      return $output;
   }
 }
 
diff --git includes/flag.admin.inc includes/flag.admin.inc
index 8ff9ffa..83c3881 100644
--- includes/flag.admin.inc
+++ includes/flag.admin.inc
@@ -26,9 +26,13 @@ function theme_flag_admin_page($variables) {
   foreach ($flags as $flag) {
     $ops = array(
       'flags_edit' =>  array('title' => t('edit'), 'href' => $flag->admin_path('edit')),
+      'flags_fields' =>  array('title' => t('manage fields'), 'href' => $flag->admin_path('fields')),
       'flags_delete' =>  array('title' => t('delete'), 'href' => $flag->admin_path('delete')),
       'flags_export' =>  array('title' => t('export'), 'href' => $flag->admin_path('export')),
     );
+    if (!module_exists('field_ui')) {
+      unset($ops['flags_fields']);
+    }
 
     $roles = array_flip(array_intersect(array_flip(user_roles()), $flag->roles['flag']));
     $rows[] = array(
diff --git includes/flag.token.inc includes/flag.token.inc
index 5cd1f4b..09e4464 100644
--- includes/flag.token.inc
+++ includes/flag.token.inc
@@ -27,6 +27,22 @@ function flag_token_info() {
     'description' => t('The human-readable flag title.'),
   );
 
+  // Flagging tokens.
+  //
+  // Attached fields are exposed as tokens via some contrib module, but we
+  // need to expose other fields ourselves. Currently, 'date' is the only such
+  // field we expose.
+  $types['flagging'] = array(
+    'name' => t('Flaggings'),
+    'description' => t('Tokens related to flaggings.'),
+    'needs-data' => 'flagging',
+  );
+  $tokens['flagging']['date'] = array(
+    'name' => t('Flagging date'),
+    'description' => t('The date an item was flagged.'),
+    'type' => 'date',
+  );
+
   // Flage action tokens.
   $types['flag-action'] = array(
     'name' => t('Flag actions'),
@@ -81,6 +97,7 @@ function flag_token_info() {
 function flag_tokens($type, $tokens, array $data = array(), array $options = array()) {
   $replacements = array();
   $sanitize = !empty($options['sanitize']);
+  $langcode = isset($options['language']) ? $options['language']->language : NULL;
 
   if ($type == 'flag' && !empty($data['flag'])) {
     $flag = $data['flag'];
@@ -95,6 +112,19 @@ function flag_tokens($type, $tokens, array $data = array(), array $options = arr
       }
     }
   }
+  elseif ($type == 'flagging' && !empty($data['flagging'])) {
+    $flagging = $data['flagging'];
+    foreach ($tokens as $name => $original) {
+      switch ($name) {
+        case 'date':
+          $replacements[$original] = format_date($flagging->timestamp, 'medium', '', NULL, $langcode);
+          break;
+      }
+    }
+    if ($date_tokens = token_find_with_prefix($tokens, 'date')) {
+      $replacements += token_generate('date', $date_tokens, array('date' => $flagging->timestamp), $options);
+    }
+  }
   elseif ($type == 'flag-action' && !empty($data['flag-action'])) {
     $action = $data['flag-action'];
     foreach ($tokens as $name => $original) {