WordPress.org

This plugin works with WordPress version 2.7 or later.

1. Unzip the ZIP file and drop the folder straight into your wp-content/plugins/ directory.
2. Activate the plugin through the 'Plugins' menu in WordPress.
3. Visit the 'Settings -> Privacy' menu in WordPress and set a global post password.

Now whenever you write or edit a post (or page) you'll be able to switch password-protection on or off with one click, instead of having to manually type in a password for each post. You can change the password whenever you like from the 'Settings -> Privacy' menu.