FAA Maps Out Real-Time Airport Status
Where are the Delays?
Check out the FAA's Real-Time Airport Status Map

The Department of Transportation (DOT) has a helpful travel tool on its FAA Web site: the real-time airport status page. Airport status is relayed via color-coding and brief updates: green, good; yellow, ummmm cautionary; and red and black...better get a good book or check an Amtrak schedule.
The
Flight Delay Information - Air Traffic Control System Command Center
http://www.fly.faa.gov/index.html
You can check for air traffic delays by using the posted map or drop-down text box. What makes this site particularly unique as well as valuable is the in-depth and up-to-the-minute accuracy of its delay information.