diff --git a/core/util.inc.php b/core/util.inc.php
index 4bf59033..7168d610 100644
--- a/core/util.inc.php
+++ b/core/util.inc.php
@@ -687,6 +687,19 @@ function set_prefixed_cookie($name, $value, $time, $path) {
 	setcookie($full_name, $value, $time, $path);
 }
 
+/**
+ * Set (or extend) a flash-message cookie
+ */
+function flash_message(/*string*/ $text) {
+	$current = get_prefixed_cookie("flash_message");
+	if($current) {
+		$text = $current . "\n" . $text;
+	}
+	# the message should be viewed pretty much immediately,
+	# so 60s timeout should be more than enough
+	set_prefixed_cookie("flash_message", $text, time()+60, "/");
+}
+
 /**
  * Figure out the path to the shimmie install directory.
  *
diff --git a/themes/danbooru/layout.class.php b/themes/danbooru/layout.class.php
index bf9763f2..ee760130 100644
--- a/themes/danbooru/layout.class.php
+++ b/themes/danbooru/layout.class.php
@@ -191,6 +191,13 @@ class Layout {
 			$withleft = "noleft";
 		}
 
+		$flash = get_prefixed_cookie("flash_message");
+		$flash_html = "";
+		if($flash) {
+			$flash_html = "<b id='flash'>".nl2br(html_escape($flash))." <a href='#' onclick=\"\$('#flash').hide(); return false;\">[X]</a></b>";
+			set_prefixed_cookie("flash_message", "", -1, "/");
+		}
+
 		print <<<EOD
 <!doctype html>
 <!--[if lt IE 7]> <html class="no-js lt-ie9 lt-ie8 lt-ie7" lang="en"> <![endif]-->
@@ -217,6 +224,7 @@ $header_html
 		$sub_block_html
 		$left
 		<article class="$withleft">
+			$flash_html
 			$main_block_html
 		</article>
 		<footer><em>
diff --git a/themes/default/layout.class.php b/themes/default/layout.class.php
index b2e4a67e..289854d1 100644
--- a/themes/default/layout.class.php
+++ b/themes/default/layout.class.php
@@ -49,6 +49,13 @@ class Layout {
 			$wrapper = ' style="height: 3em; overflow: auto;"';
 		}
 
+		$flash = get_prefixed_cookie("flash_message");
+		$flash_html = "";
+		if($flash) {
+			$flash_html = "<b id='flash'>".nl2br(html_escape($flash))." <a href='#' onclick=\"\$('#flash').hide(); return false;\">[X]</a></b>";
+			set_prefixed_cookie("flash_message", "", -1, "/");
+		}
+
 		print <<<EOD
 <!doctype html>
 <!--[if lt IE 7]> <html class="no-js lt-ie9 lt-ie8 lt-ie7" lang="en"> <![endif]-->
@@ -69,6 +76,7 @@ $header_html
 			$left_block_html	
 		</nav>
 		<article>
+			$flash_html
 			$main_block_html
 		</article>
 		<footer>
diff --git a/themes/futaba/layout.class.php b/themes/futaba/layout.class.php
index d540a20c..c98fe71f 100644
--- a/themes/futaba/layout.class.php
+++ b/themes/futaba/layout.class.php
@@ -55,6 +55,13 @@ class Layout {
 			$withleft = "";
 		}
 
+		$flash = get_prefixed_cookie("flash_message");
+		$flash_html = "";
+		if($flash) {
+			$flash_html = "<b id='flash'>".nl2br(html_escape($flash))." <a href='#' onclick=\"\$('#flash').hide(); return false;\">[X]</a></b>";
+			set_prefixed_cookie("flash_message", "", -1, "/");
+		}
+
 		print <<<EOD
 <!doctype html>
 <!--[if lt IE 7]> <html class="no-js lt-ie9 lt-ie8 lt-ie7" lang="en"> <![endif]-->
@@ -75,6 +82,7 @@ $header_html
 		</header>
 		$left
 		<article class="$withleft">
+			$flash_html
 			$main_block_html
 		</article>
 		<footer>
diff --git a/themes/lite/layout.class.php b/themes/lite/layout.class.php
index 39364bc4..127e5b21 100644
--- a/themes/lite/layout.class.php
+++ b/themes/lite/layout.class.php
@@ -159,6 +159,13 @@ class Layout {
 			$main_block_html = "<article>$main_block_html</article>";
 		}
 
+		$flash = get_prefixed_cookie("flash_message");
+		$flash_html = "";
+		if($flash) {
+			$flash_html = "<b id='flash'>".nl2br(html_escape($flash))." <a href='#' onclick=\"\$('#flash').hide(); return false;\">[X]</a></b>";
+			set_prefixed_cookie("flash_message", "", -1, "/");
+		}
+
 		print <<<EOD
 <!doctype html>
 <!--[if lt IE 7]> <html class="no-js lt-ie9 lt-ie8 lt-ie7" lang="en"> <![endif]-->
@@ -177,6 +184,7 @@ class Layout {
 			$sub_block_html
 		</header>
 		$left_block_html
+		$flash_html
 		$main_block_html
 		<footer>
 			Images &copy; their respective owners,
diff --git a/themes/warm/layout.class.php b/themes/warm/layout.class.php
index 7ddb363a..d5f70eb6 100644
--- a/themes/warm/layout.class.php
+++ b/themes/warm/layout.class.php
@@ -55,6 +55,13 @@ class Layout {
 			$wrapper = ' style="height: 3em; overflow: auto;"';
 		}
 
+		$flash = get_prefixed_cookie("flash_message");
+		$flash_html = "";
+		if($flash) {
+			$flash_html = "<b id='flash'>".nl2br(html_escape($flash))." <a href='#' onclick=\"\$('#flash').hide(); return false;\">[X]</a></b>";
+			set_prefixed_cookie("flash_message", "", -1, "/");
+		}
+
 		print <<<EOD
 <!doctype html>
 <!--[if lt IE 7]> <html class="no-js lt-ie9 lt-ie8 lt-ie7" lang="en"> <![endif]-->
@@ -83,6 +90,7 @@ $header_html
 			$left_block_html
 		</nav>
 		<article>
+			$flash_html
 			$main_block_html
 		</article>
 		<footer>
