WordPress 3.1 saw the introduction of a permanent admin bar at the top of the page for logged in users. Ideal for a blog, but not so great for those using it as a CMS for a professional website.
There are a few plugins out there, but there’s a simple fix that can be done – just add the following line to your theme’s functions.php file.
<?php add_filter( 'show_admin_bar', '__return_false' ); ?>