I just had an idea for the most amazing emacs feature -- and unfortunately, this channel is large enough to contain it, so here it comes. If I visit a file, and auto-revert-mode- is on in that buffer, and then something outside of emacs deletes the file, emacs should alert me somehow -- blinking the frame, or putting something in the mode line.
That's my idea, and it's mine, too.
Discuss.