Originally Posted by
mgcsinc
You want a movie theater at the airport?
As pointed out by exerda (though it might be a bit difficult to get there), there is a remarkable museum near the airport.
I originate from IAD so for me it's not an option to go outside the airport because of a long layover. I was thinking more in terms of a flight being delayed for a couple of hours.
Of course, the Air & Space is a good (and only) option for transiting passengers on long layovers, with one caveat - to my knowledge there isn't a locker or baggage storage facility in Dulles, so if you're going to the museum you're taking that lovely carry-on with you.