In WordPress 3.1 and later versions there is a brand new feature - the admin bar. It allows you to perform administrative tasks on your website while browsing through its front end. There are many people, however, that would like to disable this feature.
Although this admin bar can be disabled by adding a filter in your functions.php file, the easiest and cleanest way to do this is through the WordPress user configuration page.
Login with your account and then navigate to Users -> All Users menu from the left menu column. Once on this page, hover over the selected user and click on the Edit button that appears.
On the next page disable the Show Toolbar when viewing site check and save the settings. The Admin bar will no longer be displayed on the front end of your blog.