This extension just simply works. And it has a keystroke combination too (Ctrl-Shft-X). I don't know why webmasters think it's a good idea to rudely interrupt you with a stupid, pointless overlay when you're on a mission and are totally focused on something else, but this extension is the way to fight back. Many thanks to the author!

Great addon. Does exactly what it says it will do. It would be nicer if overlays could be per-emptively blocked on entire pages. For example CNN.