If it helps, we'll be staying on Dupont Circle and plan to do a lot of walking and metro-riding. I love DC, but I hate driving there (who doesn't?). I know the monuments and museums pretty well, but I don't know any nightclubs/restaurants/hotspots, so suggestions are welcome from the locals.
I've been to DC a dozen times, and it's IMHO the greatest city in the world, so I've done all the touristy stuff. Pedro has only been there once, for three hours on the way back from a wedding in Baltimore, and I dragged him through the war memorials, the Lincoln, Washington, and FDR memorials, and the Supreme Court in that brief amount of time. I'd like to do the monument walk again, at a more humane pace, but there's a whole aspect of DC I've never seen -- I take the field-trip approach, so I miss a lot of the culture -- that Pedro's probably more interested in than a bunch of old buildings.
Things that would be helpful to know:
-- Good, cheap, non-greasy places to eat
-- A couple of nice restaurants to go on a date -- preferably someplace known for their cuisine, not necessarily for the "atmosphere"
-- Someplace to get really good Chinese food
-- A couple of fun after-dinner things to do -- there's a really neat play running at Ford's Theatre which would serve a dual purpose: satisfying my need to drag Pedro to every bleedin' historical site and monument and his affinity for, you know, culture and the arts.