diff --git a/platform/platform-api/src/com/intellij/openapi/application/UserActivity.java b/platform/platform-api/src/com/intellij/openapi/application/UserActivity.java
new file mode 100644
index 000000000000..d4adfc01dc7b
--- /dev/null
+++ b/platform/platform-api/src/com/intellij/openapi/application/UserActivity.java
@@ -0,0 +1,44 @@
+/*
+ * Copyright 2000-2010 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.intellij.openapi.application;
+
+import com.intellij.util.messages.Topic;
+
+import java.awt.event.KeyEvent;
+import java.awt.event.MouseEvent;
+
+public interface UserActivity {
+
+  Topic<UserActivity> TOPIC = Topic.create("UserActivity", UserActivity.class);
+
+  void onKeyboardActivity(KeyEvent e);
+  void onMouseActivity(MouseEvent e);
+
+  void onIdle();
+
+  class Adapter implements UserActivity {
+
+    public void onKeyboardActivity(KeyEvent e) {
+    }
+
+    public void onMouseActivity(MouseEvent e) {
+    }
+
+    public void onIdle() {
+    }
+  }
+
+}
diff --git a/platform/platform-api/src/com/intellij/openapi/util/registry/RegistryValue.java b/platform/platform-api/src/com/intellij/openapi/util/registry/RegistryValue.java
index 333551b05cae..a5ef01b31473 100644
--- a/platform/platform-api/src/com/intellij/openapi/util/registry/RegistryValue.java
+++ b/platform/platform-api/src/com/intellij/openapi/util/registry/RegistryValue.java
@@ -17,6 +17,7 @@ package com.intellij.openapi.util.registry;
 
 import com.intellij.openapi.Disposable;
 import com.intellij.openapi.util.Disposer;
+import org.jetbrains.annotations.Nullable;
 
 import java.awt.*;
 import java.util.MissingResourceException;
@@ -168,13 +169,15 @@ public class RegistryValue {
     setValue(getBundleValue(myKey, true));
   }
 
-  public void addListener(final RegistryValueListener listener, Disposable parent) {
+  public void addListener(final RegistryValueListener listener, @Nullable Disposable parent) {
     myListeners.add(listener);
-    Disposer.register(parent, new Disposable() {
-      public void dispose() {
-        myListeners.remove(listener);
-      }
-    });
+    if (parent != null) {
+      Disposer.register(parent, new Disposable() {
+        public void dispose() {
+          myListeners.remove(listener);
+        }
+      });
+    }
   }
 
   @Override
diff --git a/platform/platform-impl/src/com/intellij/ide/IdeEventQueue.java b/platform/platform-impl/src/com/intellij/ide/IdeEventQueue.java
index 8eccf233039c..52eb17c923a3 100644
--- a/platform/platform-impl/src/com/intellij/ide/IdeEventQueue.java
+++ b/platform/platform-impl/src/com/intellij/ide/IdeEventQueue.java
@@ -24,6 +24,7 @@ import com.intellij.openapi.Disposable;
 import com.intellij.openapi.application.Application;
 import com.intellij.openapi.application.ApplicationManager;
 import com.intellij.openapi.application.ModalityState;
+import com.intellij.openapi.application.UserActivity;
 import com.intellij.openapi.application.impl.ApplicationImpl;
 import com.intellij.openapi.diagnostic.Logger;
 import com.intellij.openapi.keymap.impl.IdeKeyEventDispatcher;
@@ -33,12 +34,16 @@ import com.intellij.openapi.util.Condition;
 import com.intellij.openapi.util.Disposer;
 import com.intellij.openapi.util.SystemInfo;
 import com.intellij.openapi.util.registry.Registry;
+import com.intellij.openapi.util.registry.RegistryValue;
+import com.intellij.openapi.util.registry.RegistryValueListener;
 import com.intellij.openapi.wm.IdeFocusManager;
 import com.intellij.openapi.wm.ex.WindowManagerEx;
 import com.intellij.util.Alarm;
 import com.intellij.util.ReflectionUtil;
 import com.intellij.util.containers.ContainerUtil;
 import com.intellij.util.containers.HashMap;
+import com.intellij.util.messages.Topic;
+import com.intellij.util.ui.UIUtil;
 import org.jetbrains.annotations.NotNull;
 
 import javax.swing.*;
@@ -126,6 +131,14 @@ public class IdeEventQueue extends EventQueue {
 
   private final Set<Runnable> myReady = new HashSet<Runnable>();
   private boolean myKeyboardBusy;
+  private UserActivity myUserActivity = new UserActivity.Adapter();
+
+  private Runnable myIdleMessageBusNotifier = new Runnable() {
+    public void run() {
+      getUserActivity().onIdle();
+    }
+  };
+  private boolean myWasEverInstalledNotifier;
 
   private static class IdeEventQueueHolder {
     private static final IdeEventQueue INSTANCE = new IdeEventQueue();
@@ -157,6 +170,30 @@ public class IdeEventQueue extends EventQueue {
         }
       }
     });
+
+    Registry.get("actionSystem.idleTime").addListener(new RegistryValueListener() {
+      public void beforeValueChanged(RegistryValue value) {
+      }
+
+      public void afterValueChanged(RegistryValue value) {
+        installIdleMessageBusSync();
+      }
+    }, null);
+
+    installIdleMessageBusSync();
+  }
+
+  private void installIdleMessageBusSync() {
+    UIUtil.invokeLaterIfNeeded(new Runnable() {
+      public void run() {
+        if (myWasEverInstalledNotifier) {
+          removeIdleListener(myIdleMessageBusNotifier);
+        }
+
+        addIdleListener(myIdleMessageBusNotifier, Registry.intValue("actionSystem.idleTime"));
+        myWasEverInstalledNotifier = true;
+      }
+    });
   }
 
 
@@ -453,6 +490,16 @@ public class IdeEventQueue extends EventQueue {
           for (Runnable activityListener : myActivityListeners) {
             activityListener.run();
           }
+
+          if (e instanceof KeyEvent) {
+            if (e.getID() == KeyEvent.KEY_PRESSED) {
+              getUserActivity().onKeyboardActivity((KeyEvent)e);
+            }
+          } else if (e instanceof MouseEvent ){
+            if (e.getID() == MouseEvent.MOUSE_PRESSED) {
+              getUserActivity().onMouseActivity((MouseEvent)e);
+            }
+          }
         }
       }
     }
@@ -770,4 +817,12 @@ public class IdeEventQueue extends EventQueue {
       });
     }
   }
+
+  public void setApplication(Application instance) {
+    myUserActivity = instance.getMessageBus().syncPublisher(UserActivity.TOPIC);
+  }
+
+  private UserActivity getUserActivity() {
+    return myUserActivity;
+  }
 }
diff --git a/platform/platform-impl/src/com/intellij/openapi/application/ex/ApplicationManagerEx.java b/platform/platform-impl/src/com/intellij/openapi/application/ex/ApplicationManagerEx.java
index 0d43ab2172e4..6c3dae933372 100644
--- a/platform/platform-impl/src/com/intellij/openapi/application/ex/ApplicationManagerEx.java
+++ b/platform/platform-impl/src/com/intellij/openapi/application/ex/ApplicationManagerEx.java
@@ -15,6 +15,7 @@
  */
 package com.intellij.openapi.application.ex;
 
+import com.intellij.ide.IdeEventQueue;
 import com.intellij.openapi.Disposable;
 import com.intellij.openapi.application.Application;
 import com.intellij.openapi.application.ApplicationManager;
@@ -37,6 +38,7 @@ public class ApplicationManagerEx extends ApplicationManager {
 
   public static void setApplication(Application instance) {
     ourApplication = instance;
+    IdeEventQueue.getInstance().setApplication(instance);
     CachedSingletonsRegistry.cleanupCachedFields();
   }
 
@@ -49,6 +51,7 @@ public class ApplicationManagerEx extends ApplicationManager {
       }
     });
     ourApplication = instance;
+    IdeEventQueue.getInstance().setApplication(instance);
     CachedSingletonsRegistry.cleanupCachedFields();
   }
 }
diff --git a/platform/platform-impl/src/com/intellij/openapi/application/impl/ApplicationImpl.java b/platform/platform-impl/src/com/intellij/openapi/application/impl/ApplicationImpl.java
index 34233d4e8575..d5e6056c8e3a 100644
--- a/platform/platform-impl/src/com/intellij/openapi/application/impl/ApplicationImpl.java
+++ b/platform/platform-impl/src/com/intellij/openapi/application/impl/ApplicationImpl.java
@@ -59,6 +59,7 @@ import com.intellij.util.ReflectionCache;
 import com.intellij.util.concurrency.ReentrantWriterPreferenceReadWriteLock;
 import com.intellij.util.containers.ContainerUtil;
 import com.intellij.util.containers.Stack;
+import com.intellij.util.messages.Topic;
 import com.intellij.util.ui.UIUtil;
 import org.jetbrains.annotations.NonNls;
 import org.jetbrains.annotations.NotNull;
@@ -67,6 +68,8 @@ import org.picocontainer.MutablePicoContainer;
 
 import javax.swing.*;
 import java.awt.*;
+import java.awt.event.KeyEvent;
+import java.awt.event.MouseEvent;
 import java.io.IOException;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
diff --git a/platform/platform-resources-en/src/misc/registry.properties b/platform/platform-resources-en/src/misc/registry.properties
index 114dfdbf81ef..c0ebb4791941 100644
--- a/platform/platform-resources-en/src/misc/registry.properties
+++ b/platform/platform-resources-en/src/misc/registry.properties
@@ -19,6 +19,7 @@ actionSystem.mac.screenMenuNotUpdatedFix=false
 actionSystem.keyGestures.enabled=false
 actionSystem.suspendFocusTransferIfApplicationInactive=false
 actionSystem.noContextComponentWhileFocusTransfer=true
+actionSystem.idleTime=2000
 
 ide.debugMode=true
 ide.debugMode.description=Record additonal information to make bug reports more informative