diff --git a/src/java/com/threerings/stage/tools/editor/EditorFrame.java b/src/java/com/threerings/stage/tools/editor/EditorFrame.java
index e1d27db4..1a20ce30 100644
--- a/src/java/com/threerings/stage/tools/editor/EditorFrame.java
+++ b/src/java/com/threerings/stage/tools/editor/EditorFrame.java
@@ -72,7 +72,7 @@ public class EditorFrame extends ManagedJFrame
     {
         _writer = writer;
         // treat a closing window as a request to quit
-        addWindowListener(new WindowAdapter () {
+        addWindowListener(new WindowAdapter() {
             @Override
             public void windowClosing (WindowEvent e) {
                 handleQuit(null);
@@ -96,7 +96,7 @@ public class EditorFrame extends ManagedJFrame
                 System.getProperty("user.dir"));
         }
         _chooser = (target == null) ? new JFileChooser() : new JFileChooser(target);
-        _chooser.setFileFilter(new FileFilter () {
+        _chooser.setFileFilter(new FileFilter() {
             @Override public boolean accept (File f) {
                 return (f.isDirectory() || f.getName().endsWith(".xml"));
             }
@@ -272,6 +272,14 @@ public class EditorFrame extends ManagedJFrame
         accel = KeyStroke.getKeyStroke(KeyEvent.VK_M, ActionEvent.CTRL_MASK);
         MenuUtil.addMenuItem(menuActions, "Update mini view",
                              KeyEvent.VK_M, accel, this, "updateMiniView");
+
+        accel = KeyStroke.getKeyStroke(KeyEvent.VK_Z, ActionEvent.CTRL_MASK);
+        MenuUtil.addMenuItem(menuActions, "Undo",
+            KeyEvent.VK_Z, accel, this, "undo");
+
+        accel = KeyStroke.getKeyStroke(KeyEvent.VK_Y, ActionEvent.CTRL_MASK);
+        MenuUtil.addMenuItem(menuActions, "Redo",
+            KeyEvent.VK_Y, accel, this, "redo");
     }
 
     protected void setScene (StageScene scene)
@@ -494,6 +502,16 @@ public class EditorFrame extends ManagedJFrame
         _scrollBox.updateView();
     }
 
+    public void undo (ActionEvent evt)
+    {
+        _svpanel.undo();
+    }
+
+    public void redo (ActionEvent evt)
+    {
+        _svpanel.redo();
+    }
+
     /**
      * Handles a request to open the preferences dialog.
      */
diff --git a/src/java/com/threerings/stage/tools/editor/EditorScenePanel.java b/src/java/com/threerings/stage/tools/editor/EditorScenePanel.java
index 01a2d98e..0b3559cb 100644
--- a/src/java/com/threerings/stage/tools/editor/EditorScenePanel.java
+++ b/src/java/com/threerings/stage/tools/editor/EditorScenePanel.java
@@ -23,6 +23,7 @@ package com.threerings.stage.tools.editor;
 
 import java.util.ArrayList;
 import java.util.Iterator;
+import java.util.LinkedList;
 import java.util.List;
 
 import java.awt.AlphaComposite;
@@ -220,6 +221,8 @@ public class EditorScenePanel extends StageScenePanel
      */
     protected void placeTile (int x, int y)
     {
+        markCheckpoint();
+
         Rectangle drag = clearTileSelectRegion(x, y);
 
         // sanity check
@@ -250,6 +253,8 @@ public class EditorScenePanel extends StageScenePanel
      */
     protected void deleteTile (int x, int y)
     {
+        markCheckpoint();
+
         Rectangle drag = clearTileSelectRegion(x, y);
         log.info("Deleting " + drag);
 
@@ -301,6 +306,8 @@ public class EditorScenePanel extends StageScenePanel
      */
     protected void editTile (int x, int y)
     {
+        markCheckpoint();
+
         // bail if we're not hovering over a scene object
         if (_hobject == null || !(_hobject instanceof SceneObject)) {
             return;
@@ -332,6 +339,8 @@ public class EditorScenePanel extends StageScenePanel
      */
     protected void editPortal (EditablePortal portal)
     {
+        markCheckpoint();
+
         // create our portal dialog if we haven't yet
         if (_dialogPortal == null) {
             _dialogPortal = new PortalDialog(_ctx, this);
@@ -397,6 +406,8 @@ public class EditorScenePanel extends StageScenePanel
             break;
 
         case EditorModel.ACTION_PLACE_PORTAL:
+            markCheckpoint();
+
             Point fcoords = getFullCoords(mx, my);
             // mouse button three is delete
             if (event.getButton() == MouseEvent.BUTTON3) {
@@ -939,7 +950,7 @@ public class EditorScenePanel extends StageScenePanel
     /**
      * Paint the specified StageLocation
      */
-    protected void paintLocation(Graphics2D gfx, StageLocation loc, Color color, boolean highlight)
+    protected void paintLocation (Graphics2D gfx, StageLocation loc, Color color, boolean highlight)
     {
         // get the portal's center coordinate
         Point spos = new Point();
@@ -1118,6 +1129,49 @@ public class EditorScenePanel extends StageScenePanel
         }
     }
 
+    protected void markCheckpoint ()
+    {
+        _undo.preserve();
+        _redo.clear();
+    }
+
+    public void undo ()
+    {
+        if (_undo.size() > 0) {
+            _redo.preserve();
+            _undo.rollback();
+        }
+    }
+
+    public void redo ()
+    {
+        if (_redo.size() > 0) {
+            _undo.preserve();
+            _redo.rollback();
+        }
+    }
+
+    protected class UndoStack extends LinkedList<MisoSceneModel>
+    {
+        public void preserve () {
+            addFirst(_model.clone());
+
+            if (size() > MAX_UNDO_SIZE) {
+                removeLast();
+            }
+        }
+
+        public void rollback () {
+            if (size() > 0) {
+                _model = removeFirst();
+                _blocks.clear();
+                refreshScene();
+            }
+        }
+    }
+
+    protected static final int MAX_UNDO_SIZE = 20;
+
     /** Provides access to stuff. */
     protected EditorContext _ctx;
 
@@ -1177,6 +1231,9 @@ public class EditorScenePanel extends StageScenePanel
     /** The object currently being edited by the object editor dialog. */
     protected SceneObject _eobject;
 
+    protected UndoStack _undo = new UndoStack();
+    protected UndoStack _redo = new UndoStack();
+
     /** The triangle used to render a portal on-screen. */
     protected static Polygon _locTri;