WordPress 3.1 adds an admin bar, which includes a handful of links and the WordPress logo. If you are going to handout websites to a client and you want it to be brandless, here is the function to remove that WordPress logo.
function annointed_admin_bar_remove() {
global $wp_admin_bar;
/* Remove their stuff */
$wp_admin_bar->remove_menu('wp-logo');
}
add_action('wp_before_admin_bar_render', 'annointed_admin_bar_remove', 0);