diff --git a/delegator/css/task-handlers.css b/delegator/css/task-handlers.css
index b501aed0bc0b8c7552454fb3d0e08c3fcf56e7fa..e63b5d88f42747f2b45f73f30e0665c92f24691e 100644
--- a/delegator/css/task-handlers.css
+++ b/delegator/css/task-handlers.css
@@ -11,3 +11,9 @@
 .delegator-current {
   font-weight: bold;
 }
+
+.delegator-locked {
+  color: red;
+  border: 1px solid red;
+  padding: 1em;
+}
diff --git a/delegator/delegator.admin.inc b/delegator/delegator.admin.inc
index 9a9f294609b830ce74af523b4247bec7a96a764f..a78d45580f70da28322faaba64e6ea3e077e6bf2 100644
--- a/delegator/delegator.admin.inc
+++ b/delegator/delegator.admin.inc
@@ -48,6 +48,7 @@ function delegator_administer_task($task_name) {
     'subtask_id' => $subtask_id,
     'task_handlers' => $task_handlers,
     'cache' => delegator_admin_get_task_cache($task, $subtask_id, $task_handlers),
+    'task_name' => $task_name,
   );
   ctools_include('form');
   return ctools_build_form('delegator_admin_list_form', $form_state);
@@ -62,25 +63,31 @@ function delegator_administer_task($task_name) {
  * has been changed so that we can update the display when
  * it is drawn.
  */
-function delegator_admin_get_task_cache($task, $subtask_id, $task_handlers) {
+function delegator_admin_get_task_cache($task, $subtask_id, $task_handlers = NULL) {
   $key = $task['name'] . ':' . $subtask_id;
   ctools_include('object-cache');
-  $cache = ctools_object_cache_get('handlers', $key);
+  $cache = ctools_object_cache_get('delegator_handlers', $key);
 
   if (!$cache) {
     // If no cache found, create one. We don't write this, though,
     // because we only want to create this object when something
     // actually changes.
-    $cache = array();
+    if (!isset($task_handlers)) {
+      $task_handlers = delegator_load_task_handlers($task, $subtask_id);
+    }
+
+    $cache = new stdClass;
+    $cache->handlers = array();
     foreach ($task_handlers as $id => $handler) {
-      $cache[$id]['name'] = $id;
-      $cache[$id]['weight'] = $handler->weight;
-      $cache[$id]['changed'] = FALSE;
+      $cache->handlers[$id]['name'] = $id;
+      $cache->handlers[$id]['weight'] = $handler->weight;
+      $cache->handlers[$id]['changed'] = FALSE;
     }
+    $cache->locked = ctools_object_cache_test('delegator_handlers', $key);
   }
 
   // Sort the new cache.
-  uasort($cache, '_delegator_admin_task_cache_sort');
+  uasort($cache->handlers, '_delegator_admin_task_cache_sort');
 
   return $cache;
 }
@@ -92,13 +99,18 @@ function delegator_admin_get_task_cache($task, $subtask_id, $task_handlers) {
  * delegator_admin_get_task_cache().
  */
 function delegator_admin_set_task_cache($task, $subtask_id, $cache) {
+  if ($cache->locked) {
+    drupal_set_message(t('Unable to update task due to lock.'), 'error');
+    return;
+  }
+
   // First, sort the cache object.
-  uasort($cache, '_delegator_admin_task_cache_sort');
+  uasort($cache->handlers, '_delegator_admin_task_cache_sort');
 
   // Then write it.
   $key = $task['name'] . ':' . $subtask_id;
   ctools_include('object-cache');
-  $cache = ctools_object_cache_set('handlers', $key, $cache);
+  $cache = ctools_object_cache_set('delegator_handlers', $key, $cache);
 }
 
 /**
@@ -107,7 +119,7 @@ function delegator_admin_set_task_cache($task, $subtask_id, $cache) {
 function delegator_admin_clear_task_cache($task, $subtask_id) {
   ctools_include('object-cache');
   $key = $task['name'] . ':' . $subtask_id;
-  $cache = ctools_object_cache_clear('handlers', $key);
+  ctools_object_cache_clear('delegator_handlers', $key);
 }
 
 /**
@@ -115,7 +127,7 @@ function delegator_admin_clear_task_cache($task, $subtask_id) {
  */
 function delegator_admin_get_task_handler_cache($name) {
   ctools_include('object-cache');
-  return ctools_object_cache_get('task_handler', $name);
+  return ctools_object_cache_get('delegator_task_handler', $name);
 }
 
 /**
@@ -123,7 +135,7 @@ function delegator_admin_get_task_handler_cache($name) {
  */
 function delegator_admin_set_task_handler_cache($handler) {
   ctools_include('object-cache');
-  $cache = ctools_object_cache_set('task_handler', $handler->name, $handler);
+  $cache = ctools_object_cache_set('delegator_task_handler', $handler->name, $handler);
 }
 
 /**
@@ -131,7 +143,7 @@ function delegator_admin_set_task_handler_cache($handler) {
  */
 function delegator_admin_clear_task_handler_cache($name) {
   ctools_include('object-cache');
-  $cache = ctools_object_cache_clear('task_handler', $name);
+  ctools_object_cache_clear('delegator_task_handler', $name);
 }
 
 /**
@@ -184,7 +196,7 @@ function delegator_admin_list_form(&$form_state) {
   $form['#changed'] = FALSE;
 
   // Create data for a table for all of the task handlers.
-  foreach ($cache as $id => $info) {
+  foreach ($cache->handlers as $id => $info) {
     // Skip deleted items.
     if ($info['changed'] & DGA_CHANGED_DELETED) {
       $form['#changed'] = TRUE;
@@ -282,6 +294,9 @@ function delegator_admin_list_form(&$form_state) {
     '#submit' => array('delegator_admin_list_form_cancel'),
   );
 
+  $form['#delegator-lock'] = $cache->locked;
+  $form['#task-name'] = $form_state['task_name'];
+
   return $form;
 }
 
@@ -290,6 +305,16 @@ function delegator_admin_list_form(&$form_state) {
  */
 function theme_delegator_admin_list_form($form) {
   $output = '';
+  if (!empty($form['#delegator-lock'])) {
+    $account = user_load($form['#delegator-lock']->uid);
+    $name = theme('username', $account);
+    $lock_age = format_interval(time() - $form['#delegator-lock']->updated);
+    $break = url('admin/build/delegator/' . $form['#task-name'] . '/break-lock');
+
+    $output .= '<div class="delegator-locked">';
+    $output .= t('This view is being edited by user !user, and is therefore locked from editing by others. This lock is !age old. Click here to <a href="!break">break this lock</a>.', array('!user' => $name, '!age' => $lock_age, '!break' => $break));
+    $output .= '</div>';
+  }
 
   $output .= drupal_render($form['description']);
 
@@ -376,11 +401,12 @@ function delegator_admin_list_form_validate_add($form, &$form_state) {
  */
 function delegator_admin_update_weights(&$form_state) {
   // Go through our cache and check weights.
-  foreach ($form_state['cache'] as $id => $info) {
+  $handlers = &$form_state['cache']->handlers;
+  foreach ($handlers as $id => $info) {
     // update weights from form.
     if (isset($form_state['values']['handlers'][$id]['weight']) && $form_state['values']['handlers'][$id]['weight'] != $info['weight']) {
-      $form_state['cache'][$id]['weight'] = $info['weight'] = $form_state['values']['handlers'][$id]['weight'];
-      $form_state['cache'][$id]['changed'] |= DGA_CHANGED_MOVED;
+      $handlers[$id]['weight'] = $info['weight'] = $form_state['values']['handlers'][$id]['weight'];
+      $handlers[$id]['changed'] |= DGA_CHANGED_MOVED;
     }
 
     // Record the highest weight we've seen so we know what to set our addition.
@@ -390,8 +416,8 @@ function delegator_admin_update_weights(&$form_state) {
 
     // Unset any 'last touched' flag and let whatever handler is updating the
     // weights do that if it wants to.
-    if (isset($form_state['cache'][$id]['last touched'])) {
-      unset($form_state['cache'][$id]['last touched']);
+    if (isset($handlers[$id]['last touched'])) {
+      unset($handlers[$id]['last touched']);
     }
   }
 
@@ -430,7 +456,7 @@ function delegator_admin_list_form_add($form, &$form_state) {
   $name = $base;
   $count = 1;
   // If taken
-  while (isset($form_state['cache'][$name])) {
+  while (isset($form_state['cache']->handlers[$name])) {
     $name = $base . '_' . ++$count;
   }
 
@@ -452,9 +478,11 @@ function delegator_admin_list_form_add($form, &$form_state) {
   }
 
   // Store the new handler.
-  delegator_admin_set_task_handler_cache($handler);
+  if ($form_state['cache']->locked) {
+    delegator_admin_set_task_handler_cache($handler);
+  }
 
-  $form_state['cache'][$handler->name] = array(
+  $form_state['cache']->handlers[$handler->name] = array(
     'name' => $handler->name,
     'weight' => $handler->weight,
     'changed' => DGA_CHANGED_CACHED,
@@ -478,12 +506,19 @@ function delegator_admin_list_form_add($form, &$form_state) {
  */
 function delegator_admin_list_form_submit($form, &$form_state) {
   // Update the weights from the form.
+  $form_state['redirect'] = $_GET['q'];
+
   delegator_admin_update_weights($form_state);
 
   $cache = &$form_state['cache'];
+  if ($cache->locked) {
+    drupal_set_message(t('Unable to update task due to lock.'), 'error');
+    return;
+  }
+
   // Go through each of the task handlers, check to see if it needs updating,
   // and update it if so.
-  foreach ($cache as $id => $info) {
+  foreach ($cache->handlers as $id => $info) {
     // If it has been marked for deletion, delete it.
     if ($info['changed'] & DGA_CHANGED_DELETED) {
       if (isset($form_state['task_handlers'][$id])) {
@@ -514,7 +549,6 @@ function delegator_admin_list_form_submit($form, &$form_state) {
 
   // Clear the cache and set a redirect.
   delegator_admin_clear_task_cache($form_state['task'], $form_state['subtask_id']);
-  $form_state['redirect'] = $_GET['q'];
 }
 
 /**
@@ -522,7 +556,7 @@ function delegator_admin_list_form_submit($form, &$form_state) {
  */
 function delegator_admin_list_form_cancel($form, &$form_state) {
   drupal_set_message(t('All changes have been discarded.'));
-  foreach ($form_state['cache'] as $id => $info) {
+  foreach ($form_state['cache']->handlers as $id => $info) {
     if ($info['changed'] & DGA_CHANGED_CACHED) {
       // clear cached version.
       delegator_admin_clear_task_handler_cache($id);
@@ -545,11 +579,11 @@ function delegator_admin_list_form_delete($form, &$form_state) {
 
   $id = $form_state['clicked_button']['#handler'];
   // This overwrites 'moved' and 'cached' states.
-  if ($form_state['cache'][$id]['changed'] & DGA_CHANGED_CACHED) {
+  if ($form_state['cache']->handlers[$id]['changed'] & DGA_CHANGED_CACHED && !$form_state['cache']->locked) {
     // clear cached version.
     delegator_admin_clear_task_handler_cache($id);
   }
-  $form_state['cache'][$id]['changed'] = DGA_CHANGED_DELETED;
+  $form_state['cache']->handlers[$id]['changed'] = DGA_CHANGED_DELETED;
 
   // Store the changed task handler list.
   delegator_admin_set_task_cache($form_state['task'], $form_state['subtask_id'], $form_state['cache']);
@@ -573,7 +607,7 @@ function delegator_admin_list_form_config($form, &$form_state) {
   $id = $form_state['clicked_button']['#handler'];
 
   // Use the one from the database or an updated one in cache?
-  if ($form_state['cache'][$id]['changed'] & DGA_CHANGED_CACHED) {
+  if ($form_state['cache']->handlers[$id]['changed'] & DGA_CHANGED_CACHED) {
     $handler = delegator_admin_get_task_handler_cache($id);
   }
   else {
@@ -645,6 +679,7 @@ function delegator_administer_task_handler_edit($task_name, $handler_id, $name,
     'plugin_form_id' => $form_id, // so it doesn't get confused with the form's form ID
     'forms' => $plugin['edit forms'],
     'type' => 'edit',
+    'task_name' => $task_name,
   );
 
   if (!empty($plugin['forms'][$form_id]['alternate next'])) {
@@ -706,6 +741,7 @@ function delegator_administer_task_handler_add($task_id, $name, $form_id) {
     'plugin_form_id' => $form_id, // so it doesn't get confused with the form's form ID
     'forms' => $plugin['add forms'],
     'type' => 'add',
+    'task_name' => $task_name,
   );
 
   $output = '';
@@ -854,21 +890,27 @@ function delegator_admin_edit_task_handler_submit($form, &$form_state) {
 
   // Update the task handler cache to let the system know this one has now
   // officially changed.
-  $cache = delegator_admin_get_task_cache($form_state['task'], $form_state['subtask_id'], array());
+  $cache = delegator_admin_get_task_cache($form_state['task'], $form_state['subtask_id']);
+
+  $form_state['redirect'] = $form_state['clicked_button']['#next'];
+  if ($cache->locked) {
+    drupal_set_message(t('Unable to update task due to lock.'), 'error');
+    return;
+  }
 
   // Only bother updating the cache if we're going to change something, so if
   // our handler is not marked changed or is not the last touched handler, do so.
-  if (!($cache[$handler->name]['changed'] & DGA_CHANGED_CACHED) || empty($cache[$handler->name]['last touched'])) {
+  if (!($cache->handlers[$handler->name]['changed'] & DGA_CHANGED_CACHED) || empty($cache->handlers[$handler->name]['last touched'])) {
     // Clear the last touched flag from all handlers
-    foreach ($cache as $id => $info) {
+    foreach ($cache->handlers as $id => $info) {
       if (isset($info['last touched'])) {
-        unset($cache[$id]['last touched']);
+        unset($cache->handlers[$id]['last touched']);
       }
     }
 
     // Set status of our handler
-    $cache[$handler->name]['changed'] |= DGA_CHANGED_CACHED;
-    $cache[$handler->name]['last touched'] = TRUE;
+    $cache->handlers[$handler->name]['changed'] |= DGA_CHANGED_CACHED;
+    $cache->handlers[$handler->name]['last touched'] = TRUE;
     delegator_admin_set_task_cache($form_state['task'], $form_state['subtask_id'], $cache);
   }
 
@@ -879,7 +921,6 @@ function delegator_admin_edit_task_handler_submit($form, &$form_state) {
 
   // Write to cache.
   delegator_admin_set_task_handler_cache($handler);
-  $form_state['redirect'] = $form_state['clicked_button']['#next'];
 }
 
 /**
@@ -895,12 +936,64 @@ function delegator_admin_edit_task_handler_cancel($form, &$form_state) {
 
     // Send an array() through as the list of $task_handlers -- because
     // if we're at this point there MUST be something in the cache.
-    $cache = delegator_admin_get_task_cache($form_state['task'], $form_state['subtask_id'], array());
-    if (isset($cache[$form_state['handler']->name])) {
-      unset($cache[$form_state['handler']->name]);
+    $cache = delegator_admin_get_task_cache($form_state['task'], $form_state['subtask_id']);
+    if (isset($cache->handlers[$form_state['handler']->name])) {
+      unset($cache->handlers[$form_state['handler']->name]);
     }
 
     delegator_admin_set_task_cache($form_state['task'], $form_state['subtask_id'], $cache);
   }
   $form_state['redirect'] = $form_state['clicked_button']['#next'];
 }
+
+/**
+ * Form to break a lock on a delegator task.
+ */
+/**
+ * Page to delete a view.
+ */
+function delegator_administer_break_lock(&$form_state, $task_name) {
+  // Determine if the task id came in the form of TASK-SUBTASK or just TASK
+  if (strpos($task_name, '-') !== FALSE) {
+    list($task_id, $subtask_id) = explode('-', $task_name, 2);
+  }
+  else {
+    $task_id = $task_name;
+    $subtask_id = NULL;
+  }
+
+  $form_state['task_name'] = $task_name;
+  $form_state['key'] = $task_id . ':' . $subtask_id;
+
+  ctools_include('object-cache');
+  $lock = ctools_object_cache_test('delegator_handlers', $form_state['key']);
+
+  $form = array();
+
+  // @todo put task title here, but also needs subtask support.
+  if (empty($lock)) {
+    return array('message' => array('#value' => t('There is no lock on this task to break.')));
+  }
+
+  $cancel = 'admin/build/delegator/' . $task_name;
+  if (!empty($_REQUEST['cancel'])) {
+    $cancel = $_REQUEST['cancel'];
+  }
+
+  $account = user_load($lock->uid);
+  return confirm_form($form,
+                  t('Are you sure you want to break this lock?'),
+                  $cancel,
+                  t('By breaking this lock, any unsaved changes made by !user will be lost!', array('!user' => theme('username', $account))),
+                  t('Break lock'),
+                  t('Cancel'));
+}
+
+/**
+ * Submit handler to break_lock a view.
+ */
+function delegator_administer_break_lock_submit(&$form, &$form_state) {
+  ctools_object_cache_clear_all('delegator_handlers', $form_state['key']);
+  drupal_set_message(t('The lock has been broken and you may now edit this task.'));
+  $form_state['redirect'] = 'admin/build/delegator/' . $form_state['task_name'];
+}
diff --git a/delegator/delegator.module b/delegator/delegator.module
index 64f3abdb80ea00fa88be4e0ca5d7ff761c675db6..61f526aa25622d9177e4e9f09be98ef3d28776dd 100644
--- a/delegator/delegator.module
+++ b/delegator/delegator.module
@@ -95,12 +95,24 @@ function delegator_menu() {
       'file' => 'delegator.admin.inc',
     );
 
+    // Form to break a lock on this task.
+    $items['admin/build/delegator/' . $id . '/break-lock'] = array(
+      'title' => 'Break lock',
+      'page callback' => 'drupal_get_form',
+      'page arguments' => array('delegator_administer_break_lock', $id),
+      'access callback' => $access_callback,
+      'access arguments' => $access_arguments,
+      'file' => 'delegator.admin.inc',
+    );
+
     $handlers = delegator_get_task_handler_plugins($task);
     foreach ($handlers as $handler_id => $handler) {
       if (isset($handler['edit forms'])) {
         $default_task = FALSE;
         $weight = 0;
         foreach ($handler['edit forms'] as $form_id => $form_title) {
+          // The first edit form is the default for tabs, so it gets a bit
+          // of special treatment here.
           if (!$default_task) {
             $default_task = TRUE;
             $items["admin/build/delegator/$id/$handler_id/%"] = array(
diff --git a/includes/object-cache.inc b/includes/object-cache.inc
index 55d3f7b259152d957c5cf8e3a731d68030f9efc7..27333736e5d46450274a1fac569be7d9ab5029e1 100644
--- a/includes/object-cache.inc
+++ b/includes/object-cache.inc
@@ -71,6 +71,21 @@ function ctools_object_cache_clear($obj, $name) {
   db_query("DELETE FROM {ctools_object_cache} WHERE sid = '%s' AND obj = '%s' AND name = '%s'", session_id(), $obj, $name);
 }
 
+/**
+ * Remove an object from the non-volatile ctools cache for all session IDs.
+ *
+ * This is useful for clearing a lock.
+ *
+ * @param $obj
+ *   A 32 character or less string to define what kind of object is being
+ *   stored; primarily this is used to prevent collisions.
+ * @param $name
+ *   The name of the object being removed.
+ */
+function ctools_object_cache_clear_all($obj, $name) {
+  db_query("DELETE FROM {ctools_object_cache} WHERE obj = '%s' AND name = '%s'", $obj, $name);
+}
+
 /**
  * Remove all objects in the object cache that are older than the
  * specified age.
@@ -85,3 +100,23 @@ function ctools_object_cache_clean($age = NULL) {
   }
   db_query("DELETE FROM {ctools_object_cache} WHERE updated < %d", time() - $age);
 }
+
+
+/**
+ * Determine if another user has a given object cached.
+ *
+ * This is very useful for 'locking' objects so that only one user can
+ * modify them.
+ *
+ * @param $obj
+ *   A 32 character or less string to define what kind of object is being
+ *   stored; primarily this is used to prevent collisions.
+ * @param $name
+ *   The name of the object being removed.
+ *
+ * @return
+ *   An object containing the UID and updated date if found; NULL if not.
+ */
+function ctools_object_cache_test($obj, $name) {
+  return db_fetch_object(db_query("SELECT s.uid, c.updated FROM {ctools_object_cache} c INNER JOIN {sessions}  s ON c.sid = s.sid WHERE s.sid != '%s' AND c.obj = '%s' AND c.name = '%s' ORDER BY c.updated ASC", session_id(), $obj, $name));
+}