You may have noticed that there is a admin bar at the top of your website with wordpress 3.1
I think the admin bar is great as it allows me to quickly navigate between the website pages and the dashboard. When you are viewing your post, there is an option to modify if in the admin bar when before you needed to navigate to the Dashboard, then to posts and find the post to edit.
However for some the admin bar might be an annoyance. It doesn’t display you website as how your visitors will see it and it might interfere with some of your website’s functionality.
In that case, you might want to remove the admin bar from your website.
You can disable the admin bar on a per user basis by editing the user’s profile. In there, under Personal Options, you will see the option Show Admin Bar.
uncheck the option to show the admin bar “when viewing site”.
Once saved, that user will no longer see the admin bar on the website.