don't forget the Holocaust Museum......it is really good......doing things in DC is pretty cheap as most of the stuff to do is free......and yes public transit is really cheap so don't be afraid to stay in the DC suburbs and commute in....I did that for a spring break trip with the bf @ time and we had a blast

if you know politics and recognize people.....go to Congressman/Senators office...get tickets to sit in a session (boring) but cool thing to do if for nothing but a moment to see......but take the train from office building to Capital building you will see lots of politicians if they are in session at the time....

the FBI tour is really amazing
DO NOT TOUR THE PENTAGON.......too boring

and I must back up another post.....SPEND LOTS OF TIME IN THE NATIONAL MALL.....