Camera mount cover / cap?

Can anyone help me find a link to where I would order the cap / cover that covers up the mount on my 300D.. like if I had no lens attached, what I would place on the camera to prevent dust and such from getting in? I cant seem to find it on B&H..

It's called a "body cap". $6.95 plus shipping. Try a local store; it'll work out about the same unless you're going to piggyback it onto a larger order.