Sometimes at meetings, using a LCD projector, it would be useful to be able to display the contents of a text file on the screen with everything else blacked out. Just like what you can do with openoffice.org presentations or in later versions of evince (for pdfs).

Typically you displays an agenda, present meeting notes etc., and wants focus to be on the presented text, not on the application or, worse, on the desktop with all of its icons etc. Today the text must be copied to an ooo presentation to do this which seems like an un-necessary step. 

The fullscreen presentation mode should also have a "black-out" button ("B" in evince and ooo Presentation).