Index: wp-admin/plugins.php
===================================================================
--- wp-admin/plugins.php	(revision 5150)
+++ wp-admin/plugins.php	(working copy)
@@ -26,6 +26,17 @@
 		update_option('active_plugins', $current);
 		do_action('deactivate_' . trim( $_GET['plugin'] ));
 		wp_redirect('plugins.php?deactivate=true');
+	} elseif ($_GET['action'] == 'deactivate-all') {
+		check_admin_referer('deactivate-all');
+		$current = get_option('active_plugins');
+		
+		foreach ($current as $plugin) {
+			array_splice($current, array_search($plugin, $current), 1);
+			do_action('deactivate_' . $plugin);
+		}
+		
+		update_option('active_plugins', $current);
+		wp_redirect('plugins.php?deactivate-all=true');
 	}
 	exit;
 }
@@ -65,6 +76,8 @@
 	<div id="message" class="updated fade"><p><?php _e('Plugin <strong>activated</strong>.') ?></p></div>
 <?php elseif ( isset($_GET['deactivate']) ) : ?>
 	<div id="message" class="updated fade"><p><?php _e('Plugin <strong>deactivated</strong>.') ?></p></div>
+<?php elseif (isset($_GET['deactivate-all'])) : ?>
+	<div id="message" class="updated fade"><p><?php _e('All plugins <strong>deactivated</strong>.'); ?></p></div>
 <?php endif; ?>
 
 <div class="wrap">
@@ -135,6 +148,10 @@
 	}
 ?>
 
+<tr>
+	<td colspan="5"><a href="<?php echo wp_nonce_url('plugins.php?action=deactivate-all', 'deactivate-all'); ?>"><?php _e('Deactivate All Plugins'); ?></a></td>
+</tr>
+
 </table>
 <?php
 }