Let's have some more love for our nation's capitol, and some competition for those great Pittsburgh photos! (I don't live there, but my in-laws do, and I'm there several times a year and love the city.)
The World War II memorial:
Roosevelt Memorial:
Mold by
neilfein, on Flickr
Me at mile zero of the C&O, behind the boathouse:
The DC Metro is a thing of quiet beauty:
Washington Monument, and the White House (barely visible):
Rock Creek Park:
DC independence day fireworks (just 'cause it's an awesome photo):
Voyager probe model in the Air & Space museum:
Not my picture, but this is the corner of Connecticut Ave and Calvert St NW. The mural is for Salon Roi, a salon that's been there nearly as long as I've been alive:
There's also the National Zoo, the Kennedy Center (near Rock Creek Park), the national mall (the Smithsonian institute puts festivals on there pretty frequently), a large cycling community (could use more bike lanes, though)... there's no city quite like the District. If you don't get a chance to see it on this trip, that would be a shame, but it gives you something to do next time!
Here's a Flickr set of the trip Neil B and I did on the GAP and the C&O:
Shake, Rattle, and Roll! I find it hard to believe it's been nearly four years since that tour.