You have probably noticed the new Admin Bar at the top of your blog. This feature is new with version 3.1 of WordPress. It gives you quick access to a number of features, such as writing a new post or page, going to the Widgets sub-panel, going to the Dashboard, or switching between blogs if you have access permission for more than one.
You can choose to have the Admin Bar appear when you’re viewing your blog, in the Dashboard, neither, or both. To change your settings, edit your profile either by going to Users–>My Profile, or selecting Edit My Profile from the drop-down under the name of your blog on the far left in the Admin Bar itself.