Displaying Flash outside its boarders

Ok, so this might sound really impossible but its been done. Have any of you seen the ads/pop-ups that use flash and they move outside the window that the movie would be contained in? I have seen one such as a car drove out of an ad on my AIM buddy list all over my desktop, turned around and drove off the screen. I’ve tried searching here and at macromedia and came up with nothing… any help would be awsome… i have no clue how this is done…