Index: wp-includes/js/tinymce/plugins/wplink/js/wplink.dev.js
===================================================================
--- wp-includes/js/tinymce/plugins/wplink/js/wplink.dev.js	(revision 16495)
+++ wp-includes/js/tinymce/plugins/wplink/js/wplink.dev.js	(working copy)
@@ -187,6 +187,7 @@
 		this.element = element;
 		this.ul = element.children('ul');
 		this.waiting = element.find('.river-waiting');
+		this.cache = {}
 		
 		this.change( search );
 		
@@ -198,12 +199,23 @@
 			var self = this,
 				delay = this.query.page == 1 ? 0 : wpLink.minRiverAJAXDuration,
 				response = wpLink.delayedCallback( function( results, params ) {
+					// Cache the results
+					if( ! self.cache[self._search] ) {
+						self.cache[self._search] = {
+							results: results,
+							params: params
+						}
+					}
 					self.process( results, params );
 					if ( callback )
 						callback( results, params );
 				}, delay );
 			
-			this.query.ajax( response );
+			// If the search results are already cached, we can avoid an AJAX call
+			if( this.cache[this._search] )
+				response( this.cache[this._search]['results'], this.cache[this._search]['params'] );
+			else 
+				this.query.ajax( response );
 		},
 		change: function( search ) {
 			if ( this.query && this._search == search )