Well
I have had terrible luck with a tripod.
I wanted to shoot monuments at night, and was forced to take my tripod down at the following monuments/memorials
- Lincoln (Even down at the bottom of the steps)
- WWII memorial (For "Respect", even though tourist nimrods were blasting their P&S flash all over the place in pitch black, I guess that was ok)
- Washington Monument (At the base)
- White House (First tried to use it on the sidewalk, was told had to put it on the street, so I did. Then a different officer came and told me I had to be ACROSS the street)
- Then I gave up using a tripod.
SO-----------
• Bring a UWA for neat shots of buildings
• Bring a fast lens with IS (I had my 17-55 2.8IS luckily) to shoot at night or inside museums (No flash in them)
• Bring comfortable shoes!
• Bring a Gorilla pod (If you have one), as the main reason I was told to put my tripod away was "It obstructs the walking path"
• Bring your game face, it's a hectic city. Be prepared to have to walk up the escalators if you want to blend in, get bumped into with no apologies, etc.
However, its also an AWESOME city. Be sure to check out the Washington Monument, Korean War Memorial(Favorite), Jefferson, Vietnam, WWII, Air and Space Museum, Portrait Gallery, Modern Art Museum.
Edit: I saw someone posted on the American Indian cafeteria, my favorite was the portrait galleries. Awesome rotunda type place to eat, and they have a bangin' salad bar.