Index: wp-admin/css/wp-admin.dev.css
===================================================================
--- wp-admin/css/wp-admin.dev.css	(revision 16472)
+++ wp-admin/css/wp-admin.dev.css	(working copy)
@@ -269,6 +269,10 @@
 	float: right;
 	margin: -5px 0 0;
 }
+p.search-box.loading {
+	background: url(../images/wpspin_light.gif) no-repeat left center;
+	padding-left: 20px;
+}
 
 
 /*------------------------------------------------------------------------------
Index: wp-admin/js/list-table.dev.js
===================================================================
--- wp-admin/js/list-table.dev.js	(revision 16472)
+++ wp-admin/js/list-table.dev.js	(working copy)
@@ -223,8 +223,10 @@
 		ev.preventDefault();
 		ev.stopImmediatePropagation();
 
-		var data = $(this).parent('.search-box').find(':input').serializeObject();
+		var $parent = $(this).parent('.search-box').trigger('loading.start');
 
+		var data = $parent.find(':input').serializeObject();
+
 		listTable.update_rows(data, true, function() {
 			$('h2 .subtitle').remove();
 
@@ -232,10 +234,16 @@
 				$('h2').append($('<span class="subtitle">').html(
 					listTableL10n.search.replace('%s', this.htmlencode(data.s))
 				));
+			$parent.trigger('loading.end');
 		});
 	}
 	$('.search-box :submit').click(change_search);
 	$('.search-box :text').keypress(change_search);
+	$('.search-box').bind('loading.start', function() {
+		$(this).addClass('loading');
+	}).bind('loading.end', function() {
+		$(this).removeClass('loading');
+	});
 
 	// tablenav dropdowns
 	$('#post-query-submit').click(function() {