I've been meaning to whip up a browser extension that streamlines the Open web inspector - find offending node on page - delete div element work flow.
There are some out there that sort of do what I want, but I really just want to right click on the annoying popup/ad/whatever and select delete from the contextual menu, or something like that.
Pop-ups suck, and I wish my browser's pop-up blocker would also block these inline e-mail asking dialogs in every site.