We took it pretty easy. Mai, Charles and I went to the International Spy Museum, right next door to the FBI building. I loved it... reading all the exhibits, seeing the various gizmos and gadgets on display, it was pretty interesting overall. On a previous trip to the DC area, I went to visit the National Cryptologic Museum at NSA headquarters in Fort Meade, MD, which was also very interesting to me.
The Spy Museum was of more general interest, and had a few fun interactive displays. There was a recording of WWII Navajo code-talkers, a crawl space where you had to move as quietly as possible, and a covert agent game to play! Upon entry to the Spy Museum, you could spend 2 or 3 minutes learning a secret identity and then answer questions and get further instructions inside the museum. At the exit, there was a final quiz that simulated a border guard at a passport control, asking questions about your trip. Any inconsistencies resulted in a "suspicious" rating, with possible detention. Fortunately, I managed to pass through with no problems. ;)
It was rainy and after finishing up at the museum, we just wanted to get back to the hotel and rest up. Our final carbo loading spaghetti dinner was at the Pentagon City Mall food court, since it was cheap, convenient, and fast. We watched Baby Mama while unwinding in the room.