diff --git a/effects.cpp b/effects.cpp
index 924af0b4ab..f529f79a6a 100644
--- a/effects.cpp
+++ b/effects.cpp
@@ -288,6 +288,11 @@ int EffectsHandlerImpl::numberOfDesktops() const
     return Workspace::self()->numberOfDesktops();
     }
 
+void EffectsHandlerImpl::setCurrentDesktop( int desktop )
+    {
+    Workspace::self()->setCurrentDesktop( desktop );
+    }
+
 QString EffectsHandlerImpl::desktopName( int desktop ) const
     {
     return Workspace::self()->desktopName( desktop );
diff --git a/effects.h b/effects.h
index ae017e7a2c..7472d75ff7 100644
--- a/effects.h
+++ b/effects.h
@@ -39,6 +39,7 @@ class EffectsHandlerImpl : public EffectsHandler
 
         virtual int currentDesktop() const;
         virtual int numberOfDesktops() const;
+        virtual void setCurrentDesktop( int desktop );
         virtual QString desktopName( int desktop ) const;
         virtual int displayWidth() const;
         virtual int displayHeight() const;
diff --git a/effects/desktopgrid.cpp b/effects/desktopgrid.cpp
index c50c732241..23e681ec97 100644
--- a/effects/desktopgrid.cpp
+++ b/effects/desktopgrid.cpp
@@ -13,6 +13,7 @@ License. See the file "COPYING" for the exact licensing terms.
 #include <kaction.h>
 #include <kactioncollection.h>
 #include <klocale.h>
+#include <qevent.h>
 
 namespace KWin
 {
@@ -22,6 +23,7 @@ KWIN_EFFECT( DesktopGrid, DesktopGridEffect )
 DesktopGridEffect::DesktopGridEffect()
     : progress( 0 )
     , activated( false )
+    , keyboard_grab( false )
     {
     KActionCollection* actionCollection = new KActionCollection( this );
     KAction* a = static_cast< KAction* >( actionCollection->addAction( "ShowDesktopGrid" ));
@@ -42,6 +44,15 @@ void DesktopGridEffect::prePaintScreen( int* mask, QRegion* region, int time )
         // so with normal screen painting second screen paint would erase parts of the first paint
         if( progress != 0 )
             *mask |= PAINT_SCREEN_TRANSFORMED | PAINT_SCREEN_BACKGROUND_FIRST;
+        if( !activated && progress == 0 )
+            finish();
+        int d = posToDesktop( cursorPos());
+        if( d != hover_desktop )
+            {
+            *region |= desktopRect( hover_desktop, true );
+            hover_desktop = d;
+            *region |= desktopRect( hover_desktop, true );
+            }
         }
     effects->prePaintScreen( mask, region, time );
     }
@@ -85,6 +96,16 @@ void DesktopGridEffect::paintScreen( int mask, QRegion region, ScreenPaintData&
         }
     }
 
+void DesktopGridEffect::paintWindow( EffectWindow* w, int mask, QRegion region, WindowPaintData& data )
+    {
+    if( progress != 0 )
+        {
+        if( painting_desktop != hover_desktop )
+            data.brightness *= 0.7;
+        }
+    effects->paintWindow( w, mask, region, data );    
+    }
+
 void DesktopGridEffect::postPaintScreen()
     {
     if( activated ? progress != 1 : progress != 0 )
@@ -93,7 +114,7 @@ void DesktopGridEffect::postPaintScreen()
     }
 
 // Gives a position of the given desktop when all desktops are arranged in a grid
-QRect DesktopGridEffect::desktopRect( int desktop, bool scaled )
+QRect DesktopGridEffect::desktopRect( int desktop, bool scaled ) const
     {
     int x, y;
     Qt::Orientation orientation;
@@ -116,18 +137,79 @@ QRect DesktopGridEffect::desktopRect( int desktop, bool scaled )
     return rect;
     }
 
+int DesktopGridEffect::posToDesktop( const QPoint& pos ) const
+    {
+    for( int desktop = 1; // TODO could be perhaps optimized
+         desktop <= effects->numberOfDesktops();
+         ++desktop )
+        {
+        if( desktopRect( desktop, true ).contains( pos ))
+            return desktop;
+        }
+    return 0;
+    }
+
 void DesktopGridEffect::desktopChanged( int )
     {
-    if( activated )
-        toggle();
+    setActive( false );
     }
 
 void DesktopGridEffect::toggle()
     {
-    activated = !activated;
+    setActive( !activated );
+    }
+    
+void DesktopGridEffect::setActive( bool active )
+    {
+    if( activated == active )
+        return;
+    activated = active;
+    if( activated && progress == 0 )
+        setup();
     effects->addRepaintFull();
     }
 
+void DesktopGridEffect::setup()
+    {
+    keyboard_grab = effects->grabKeyboard( this );
+    input = effects->createInputWindow( this, 0, 0, displayWidth(), displayHeight(),
+        Qt::PointingHandCursor );
+    hover_desktop = effects->currentDesktop();
+    }
+
+void DesktopGridEffect::finish()
+    {
+    if( keyboard_grab )
+        effects->ungrabKeyboard();
+    keyboard_grab = false;
+    effects->destroyInputWindow( input );
+    effects->addRepaintFull(); // to get rid of hover
+    }
+
+void DesktopGridEffect::windowInputMouseEvent( Window, QEvent* e )
+    {
+    if( e->type() == QEvent::MouseButtonPress )
+        {
+        effects->setCurrentDesktop( posToDesktop( static_cast< QMouseEvent* >( e )->pos()));
+        setActive( false );
+        }
+    if( e->type() == QEvent::MouseMove )
+        {
+        int d = posToDesktop( static_cast< QMouseEvent* >( e )->pos());
+        if( d != hover_desktop )
+            {
+            effects->addRepaint( desktopRect( hover_desktop, true ));
+            hover_desktop = d;
+            effects->addRepaint( desktopRect( hover_desktop, true ));
+            }
+        }
+    }
+
+void DesktopGridEffect::grabbedKeyboardEvent( QKeyEvent* e )
+    {
+    // TODO
+    }
+
 } // namespace
 
 #include "desktopgrid.moc"
diff --git a/effects/desktopgrid.h b/effects/desktopgrid.h
index f196c83f5a..4d95daa781 100644
--- a/effects/desktopgrid.h
+++ b/effects/desktopgrid.h
@@ -27,14 +27,24 @@ class DesktopGridEffect
         virtual void paintScreen( int mask, QRegion region, ScreenPaintData& data );
         virtual void postPaintScreen();
         virtual void prePaintWindow( EffectWindow* w, int* mask, QRegion* paint, QRegion* clip, int time );
+        virtual void paintWindow( EffectWindow* w, int mask, QRegion region, WindowPaintData& data );
         virtual void desktopChanged( int old );
+        virtual void windowInputMouseEvent( Window w, QEvent* e );
+        virtual void grabbedKeyboardEvent( QKeyEvent* e );
     private slots:
         void toggle();
     private:
-        QRect desktopRect( int desktop, bool scaled );
+        QRect desktopRect( int desktop, bool scaled ) const;
+        int posToDesktop( const QPoint& pos ) const;
+        void setActive( bool active );
+        void setup();
+        void finish();
         float progress;
         bool activated;
         int painting_desktop;
+        int hover_desktop;
+        Window input;
+        bool keyboard_grab;
     };
 
 } // namespace
diff --git a/lib/kwineffects.h b/lib/kwineffects.h
index 04b837264f..f4ae1251fd 100644
--- a/lib/kwineffects.h
+++ b/lib/kwineffects.h
@@ -188,6 +188,7 @@ class KWIN_EXPORT EffectsHandler
         // 
         virtual int currentDesktop() const = 0;
         virtual int numberOfDesktops() const = 0;
+        virtual void setCurrentDesktop( int desktop ) = 0;
         virtual QString desktopName( int desktop ) const = 0;
         virtual QRect clientArea( clientAreaOption, const QPoint& p, int desktop ) const = 0;
         virtual void calcDesktopLayout(int* x, int* y, Qt::Orientation* orientation) const = 0;