Clever flights delayed visualization from FlightAware.
Appropriately called Misery Map. Shows the main airports at a glance. If you hover your mouse, like I've done for NYC below, it also tells you which legs are delayed.
Does not have every combination, but such a clever way to know overall status and then drill down by routes. Stinks to be in Chicago today!
Play with it here: http://goo.gl/0jbY0B