This still will remove all unnecessary elements from the BBC iPlayer and re-arrange the menu so that the entire page is the width of the video. This makes it suitable for smaller screens, or being displayed in the Firefox sidebar (Add a favourite, and select "open in sidebar" from the properties) so you can browse other sites while watching the video.

If you intend to use it with the sidebar, you should also install Firefox - Sidebar without size restrictions by Roland de Ruiter@userstyles.