Among the interesting items at the Newseum was this copy of the Philadelphia Inquirer from shortly after Abraham Lincoln's assassination. The Inquirer hasn't really changed much since 1865.
I'm not big on zoos, but I did go see the giant pandas at the National Zoo. I didn't nearly see all of the zoo, though. After seeing a seemingly endless number of birds, I got bored and left.
I also took time to see the National World War II Memorial and the Martin Luther King, Jr. Memorial, and took a number of photos of the Washington Monument (which was closed for repairs due to earthquake damage) -- I wish the fencing hadn't been around when I took this one.