The WordPress admin bar, introduced in version 3.1 is cool and useful, but sometimes it gets in the way of admins and other logged in users (especially to developers, who are currently working on a website’s header).
Here is a simple PHP snippet that will get rid of the admin bar. You can bring it back by just removing these three lines.
wp_deregister_script('admin-bar'); wp_deregister_style('admin-bar'); remove_action('wp_footer','wp_admin_bar_render',1000);
These go in your theme’s functions.php file.