Index: rules/base.o_s.part
===================================================================
RCS file: /cvs/xkeyboard-config/xkeyboard-config/rules/base.o_s.part,v
retrieving revision 1.30
diff -u -i -w -b -B -r1.30 base.o_s.part
--- rules/base.o_s.part	22 Apr 2008 19:54:11 -0000	1.30
+++ rules/base.o_s.part	30 Apr 2008 19:39:43 -0000
@@ -24,6 +24,7 @@
   grp:alt_caps_toggle   =       +group(alt_caps_toggle)
   grp:ctrl_alt_toggle	=	+group(ctrl_alt_toggle)
   grp:alt_shift_toggle	=	+group(alt_shift_toggle)
+  grp:alt_space_toggle	=	+group(alt_space_toggle)
   grp:menu_toggle	=	+group(menu_toggle)
   grp:lwin_toggle	=	+group(lwin_toggle)
   grp:rwin_toggle	=	+group(rwin_toggle)
Index: rules/base.xml.in
===================================================================
RCS file: /cvs/xkeyboard-config/xkeyboard-config/rules/base.xml.in,v
retrieving revision 1.253
diff -u -i -w -b -B -r1.253 base.xml.in
--- rules/base.xml.in	22 Apr 2008 20:33:53 -0000	1.253
+++ rules/base.xml.in	30 Apr 2008 19:39:52 -0000
@@ -4030,6 +4030,12 @@
       </option>
       <option>
         <configItem>
+          <name>grp:alt_space_toggle</name>
+          <_description>Alt+Space change layout.</_description>
+        </configItem>
+      </option>
+      <option>
+        <configItem>
           <name>grp:menu_toggle</name>
           <_description>Menu key changes layout.</_description>
         </configItem>
Index: symbols/group
===================================================================
RCS file: /cvs/xkeyboard-config/xkeyboard-config/symbols/group,v
retrieving revision 1.14
diff -u -i -w -b -B -r1.14 group
--- symbols/group	7 Apr 2008 21:28:16 -0000	1.14
+++ symbols/group	30 Apr 2008 19:39:54 -0000
@@ -333,3 +333,15 @@
   key <I219>  { [ ISO_Next_Group, ISO_Prev_Group ] };
 };
 
+partial modifier_keys
+xkb_symbols "alt_space_toggle" {
+    virtual_modifiers Alt;
+    key <LALT> {
+    symbols[Group1]= [ NoSymbol,    ISO_Prev_Group ],
+    virtualMods= Alt
+    };
+    key <SPCE> {
+    type[Group1]="PC_ALT_LEVEL2",
+    symbols[Group1]= [ space,   ISO_Next_Group ]
+    };
+};