diff -r e224d60a1edd multiselect/multiselect.js
--- a/multiselect/multiselect.js	Thu Apr 04 13:36:50 2013 +0200
+++ b/multiselect/multiselect.js	Thu Apr 04 15:11:22 2013 +0200
@@ -45,6 +45,18 @@
         selclass = '.' + this.id + '_sel';
         $(selclass).moveSelectionTo($(unselclass));
       });
+  
+      // Moves up selection if move up is clicked to selected box
+      $('li.multiselect_move_up:not(.multiselect-move-up-processed)', context).addClass('multiselect-move-up-processed').click(function() {
+        selclass = '.' + this.id + '_sel';
+        $(selclass).moveUp();
+      });
+  
+      // Moves down selection if move down is clicked to selected box
+      $('li.multiselect_move_down:not(.multiselect-move-down-processed)', context).addClass('multiselect-move-down-processed').click(function() {
+        selclass = '.' + this.id + '_sel';
+        $(selclass).moveDown();
+      });
     }
   };
 })(jQuery);
@@ -116,4 +128,32 @@
       }
     }
   });
-}
\ No newline at end of file
+}
+
+// Move up an option
+// usage $('nameofselectbox').moveUp();
+jQuery.fn.moveUp = function() {
+  this.each(function() {
+    for (var x=this.options.length-1;x>=0;x--) {
+      option = this.options[x];
+      if (option.selected) {
+        jQuery(option).insertBefore(jQuery(option).prev());
+        return;
+      }
+    }
+  });
+}
+
+// Move down an option
+// usage $('nameofselectbox').moveDown();
+jQuery.fn.moveDown = function() {
+  this.each(function() {
+    for (var x=this.options.length-1;x>=0;x--) {
+      option = this.options[x];
+      if (option.selected) {
+        jQuery(option).insertAfter(jQuery(option).next());
+        return;
+      }
+    }
+  });
+}
diff -r e224d60a1edd multiselect/multiselect.module
--- a/multiselect/multiselect.module	Thu Apr 04 13:36:50 2013 +0200
+++ b/multiselect/multiselect.module	Thu Apr 04 15:11:22 2013 +0200
@@ -226,6 +226,8 @@
   $prefix_post .= "<ul id=\"multiselect_btns" . "_" . $element['#field_name'] . "\" class=\"multiselect_btns\">
 <li class=\"multiselect_add\" id=\"" . $element['#field_name'] . "\"><a href=\"javascript:;\">Add</a></li>
 <li class=\"multiselect_remove\" id=\"" . $element['#field_name'] . "\"><a href=\"javascript:;\">Remove</a></li>
+<li class=\"multiselect_move_up\" id=\"" . $element['#field_name'] . "\"><a href=\"javascript:;\">Move Up</a></li>
+<li class=\"multiselect_move_down\" id=\"" . $element['#field_name'] . "\"><a href=\"javascript:;\">Move Down</a></li>
 </ul>";
 
   $widget['selected_options'] = $selected_options;