Index: source/blender/include/BSE_headerbuttons.h
===================================================================
--- source/blender/include/BSE_headerbuttons.h	(revision 10754)
+++ source/blender/include/BSE_headerbuttons.h	(working copy)
@@ -141,6 +141,7 @@
 void do_view3d_select_faceselmenu(void *arg, int event);
 void do_view3d_select_meshmenu(void *arg, int event);
 void do_view3d_select_curvemenu(void *arg, int event);
+void do_view3d_select_metaballmenu(void *arg, int event);
 void do_view3d_edit_snapmenu(void *arg, int event);
 void do_view3d_edit_mirrormenu(void *arg, int event);
 void do_view3d_transform_moveaxismenu(void *arg, int event);
Index: source/blender/include/BDR_editmball.h
===================================================================
--- source/blender/include/BDR_editmball.h	(revision 10754)
+++ source/blender/include/BDR_editmball.h	(working copy)
@@ -42,6 +42,8 @@
  */
 void add_primitiveMball(int);
 void deselectall_mball(void);
+void selectinverse_mball(void);
+void selectrandom_mball(void);
 void mouse_mball(void);
 void adduplicate_mball(void);
 void delete_mball(void); 
Index: source/blender/src/editmball.c
===================================================================
--- source/blender/src/editmball.c	(revision 10754)
+++ source/blender/src/editmball.c	(working copy)
@@ -30,6 +30,7 @@
  * ***** END GPL/BL DUAL LICENSE BLOCK *****
  */
 
+#include <math.h>
 #include <string.h>
 
 #ifdef HAVE_CONFIG_H
@@ -40,6 +41,7 @@
 
 #include "BLI_blenlib.h"
 #include "BLI_arithb.h"
+#include "BLI_rand.h"
 
 #include "DNA_screen_types.h"
 #include "DNA_space_types.h"
@@ -225,6 +227,36 @@
 	BIF_undo_push("Add MetaElem");
 }
 
+/* should be put in some more reusable place and used in each "select random" */
+static void generate_pickable_list(int *list, int size, int pickamount)
+{
+	int i, j, removable;
+	
+	BLI_srand( BLI_rand() ); /* random seed */
+
+	/* generate list in form 0->1, 1->2, 2->3, ... i-2->i-1, i->0 */
+	for(i=0; i<size; i++) {
+		if(i == size-1) list[i]= 0;
+		else list[i]= i+1;
+	}
+
+	for(i=0; i<size-pickamount; i++) { 
+		removable= floor(BLI_frand()*(size-1)+0.5); /* with rounding. frand returns [0,1] */
+		
+		/* seek proper item as the one randomly selected might not be appropriate */
+		for(j=0; j<size; j++, removable++) {
+			if(list[removable] != -1) break;
+			if(removable == size-1) removable= -1;
+		}
+				
+		/* pick unwanted item out of the list */
+		list[list[removable]]= -1; /* mark former last as invalid */
+
+		if(list[removable] == size-1) list[removable]= 0;
+		else list[removable]= list[removable]+1;
+	}
+}
+
 /* deselect all MetaElements */
 void deselectall_mball()
 {
@@ -251,6 +283,53 @@
 	BIF_undo_push("Deselect MetaElem");
 }
 
+/* inverts metaball selection */
+void selectinverse_mball()
+{
+	MetaElem *ml;
+	
+	ml= editelems.first;
+	while(ml) {
+		if(ml->flag & SELECT) ml->flag &= ~SELECT;
+		else ml->flag |= SELECT;
+		ml= ml->next;
+	}
+
+	allqueue(REDRAWVIEW3D, 0);
+	countall();
+	BIF_undo_push("Invert MetaElem");
+}
+
+/* select random metaball selection */
+void selectrandom_mball()
+{
+	MetaElem *ml;
+	static short randfac= 50;
+	int amounttoselect, i= 0, totamount= G.totvert;
+	int *itemstobeselected;	
+
+	if(!button(&randfac,0, 100,"Percentage:")) return;
+
+	if(randfac == 0) return;
+	
+	itemstobeselected= MEM_callocN(sizeof(int) * totamount, "selectitems"); /* there might be a nicer way to get amount of metaballs */
+	amounttoselect= floor(randfac * totamount / 100 + 0.5);
+	generate_pickable_list(itemstobeselected, totamount, amounttoselect);
+
+	ml= editelems.first;
+	while(ml) {
+		if(itemstobeselected[i] != -1) ml->flag |= SELECT;
+		i++;
+		ml= ml->next;
+	}
+
+	MEM_freeN(itemstobeselected);
+
+	allqueue(REDRAWVIEW3D, 0);
+	countall();
+	BIF_undo_push("Random MetaElem");
+}
+
 /* select MetaElement with mouse click (user can select radius circle or
  * stiffness circle) */
 void mouse_mball()
Index: source/blender/src/header_view3d.c
===================================================================
--- source/blender/src/header_view3d.c	(revision 10754)
+++ source/blender/src/header_view3d.c	(working copy)
@@ -1155,7 +1155,7 @@
 	return block;
 }
 
-static void do_view3d_select_metaballmenu(void *arg, int event)
+void do_view3d_select_metaballmenu(void *arg, int event)
 {
 
 	switch(event) {
@@ -1165,6 +1165,12 @@
 		case 2: /* Select/Deselect all */
 			deselectall_mball();
 			break;
+		case 3: /* Inverse */
+			selectinverse_mball();
+			break;
+		case 4: /* Select Random */
+			selectrandom_mball();
+			break;
 	}
 	allqueue(REDRAWVIEW3D, 0);
 }
@@ -1183,7 +1189,13 @@
 	uiDefBut(block, SEPR, 0, "", 0, yco-=6, menuwidth, 6, NULL, 0.0, 0.0, 0, 0, "");
 	
 	uiDefIconTextBut(block, BUTM, 1, ICON_BLANK1, "Select/Deselect All|A", 0, yco-=20, menuwidth, 19, NULL, 0.0, 0.0, 1, 2, "");
+
+	uiDefIconTextBut(block, BUTM, 1, ICON_BLANK1, "Inverse", 0, yco-=20, menuwidth, 19, NULL, 0.0, 0.0, 1, 3, "");
 		
+	uiDefBut(block, SEPR, 0, "", 0, yco-=6, menuwidth, 6, NULL, 0.0, 0.0, 0, 0, "");
+
+	uiDefIconTextBut(block, BUTM, 1, ICON_BLANK1, "Random...", 0, yco-=20, menuwidth, 19, NULL, 0.0, 0.0, 1, 4, "");
+
 	if(curarea->headertype==HEADERTOP) {
 		uiBlockSetDirection(block, UI_DOWN);
 	}
Index: source/blender/src/toolbox.c
===================================================================
--- source/blender/src/toolbox.c	(revision 10754)
+++ source/blender/src/toolbox.c	(working copy)
@@ -960,6 +960,15 @@
 {	0, "Less|Ctrl NumPad -",	10, NULL},
 {  -1, "", 				0, do_view3d_select_curvemenu}};
 
+static TBitem tb_mball_select[]= {
+{	0, "Border Select|B", 	0, NULL},
+{	0, "SEPR", 		0, NULL},
+{	0, "(De)select All|A", 	2, NULL},
+{	0, "Inverse", 		3, NULL},
+{	0, "SEPR",		0, NULL},
+{	0, "Random...",		4, NULL},
+{  -1, "",                      0, do_view3d_select_metaballmenu}};
+
 static TBitem tb__select[]= {
 {       0, "Border Select|B",   'b', NULL},
 {       0, "(De)select All|A",  'a', NULL},
@@ -2019,7 +2028,7 @@
 				case OB_MBALL:
 					menu1= addmenu_meta;
 					menu2= tb_edit;
-					menu3= tb__select;
+					menu3= tb_mball_select;
 					menu4= tb_transform_editmode2;
 					menu5= tb_obdata; str5= "Meta";
 				break;