Index: typo3/sysext/install/mod/class.tx_install.php
===================================================================
--- typo3/sysext/install/mod/class.tx_install.php	(revision 7577)
+++ typo3/sysext/install/mod/class.tx_install.php	(working copy)
@@ -226,7 +226,8 @@
 		'cleanup' => 'Clean up database',
 		'phpinfo' => 'phpinfo()',
 		'typo3conf_edit' => 'Edit files in typo3conf/',
-		'about' => 'About'
+		'about' => 'About',
+		'logout' => 'Logout of Install Tool',
 	);
 	var $JSmessage = '';
 
@@ -272,7 +273,7 @@
 		if ($_GET['TYPO3_INSTALL']['type']) {
 			$allowedTypes = array(
 				'config', 'database', 'update', 'images', 'extConfig',
-				'typo3temp', 'cleanup', 'phpinfo', 'typo3conf_edit', 'about'
+				'typo3temp', 'cleanup', 'phpinfo', 'typo3conf_edit', 'about', 'logout'
 			);
 
 			if (in_array($_GET['TYPO3_INSTALL']['type'], $allowedTypes)) {
@@ -738,6 +739,10 @@
 					$this->silent=0;
 					$this->typo3conf_edit();
 				break;
+				case 'logout':
+					session_destroy();
+					t3lib_utility_Http::redirect($this->scriptSelf);
+				break;
 				case 'about':
 				default:
 					$this->silent=0;
Index: typo3/sysext/install/Resources/Public/Stylesheets/general.css
===================================================================
--- typo3/sysext/install/Resources/Public/Stylesheets/general.css	(revision 7577)
+++ typo3/sysext/install/Resources/Public/Stylesheets/general.css	(working copy)
@@ -268,6 +268,10 @@
 	background-image: url('../Images/menuAbout.png');
 }
 
+#t3-install-menu #t3-install-menu-logout {
+	background-image: url('../Images/login-icon-key.gif');
+}
+
 #t3-install-links {
 	margin: 2em 0 0 0.8em;
 	padding: 0;