I'm sorry to disappoint, but I barely wisked through Georgetown, which I really, really, wanted to check out. I missed a lot of things I would have liked to see - Georgetown, Alexandria, Museum of the American Indian, and had I had a car, would have seen the urban poverty for myself.
I'm thinking of renting a car and hitting several cities in that part of the world, perhaps in 2008. Baltimore's off my list now, but Philly and Pittsburgh are on my list (haven't been to either), as well as a few rural areas like Harper's Ferry and rural Pennsylvania. I might swing by DC and add two days to the trip.