Set the task bar to AutoHide

>Hi everybody,
>
>In the bottom toolbar of my screen I have icons for many opened applications. When my mouse is over them, they display an image of that application in a bigger form. This image often stands in a way of my other work. Say, I'm trying to post a new message in MSDN and the image of another application obscures the Submit button.
>
>Is there a way to make these images show for a shorter duration of time or now show at all unless I click on the application icon?
>
>Thanks in advance.