diff -ru VirtualBox-3.1.8_OSE.original/src/VBox/Frontends/VBoxSDL/VBoxSDL.cpp VirtualBox-3.1.8_OSE/src/VBox/Frontends/VBoxSDL/VBoxSDL.cpp
--- VirtualBox-3.1.8_OSE.original/src/VBox/Frontends/VBoxSDL/VBoxSDL.cpp	Mon May 10 08:46:18 2010
+++ VirtualBox-3.1.8_OSE/src/VBox/Frontends/VBoxSDL/VBoxSDL.cpp	Sun May 30 22:17:39 2010
@@ -703,6 +703,7 @@
              "               q           Power off\n"
              "               r           VM reset\n"
              "               s           Save state and power off\n"
+	     "               z           Iconify window\n"
              "              <del>        Send <ctrl><alt><del>\n"
              "       <F1>...<F12>        Send <ctrl><alt><Fx>\n"
 #if defined(DEBUG) || defined(VBOX_WITH_STATISTICS)
@@ -4779,6 +4780,16 @@
             break;
         }
 
+        case SDLK_z:
+	{
+	    if(strchr(gHostKeyDisabledCombinations, 'z'))
+	    {
+		return VERR_NOT_SUPPORTED;
+	    }
+	    SDL_WM_IconifyWindow();
+	    break;
+	}
+
         /*
          * Pause / Resume toggle.
          */