We also went to the National Cathedral that weekend, a first for all of us. This is a shot of the highest tower from the Bishop's Garden.
The highlight of the Cathedral was riding the elevator to the viewing platform in the highest tower. You can walk around and see all of DC from there. We could even see the LDS temple way off in the distance.
We all loved the stained glass. There was a lot of it and it was so beautiful. We also really enjoyed looking at the gargoyles on the outside of the building, though the cold kept us from doing that as long as we would have liked. Our favorite was the Darth Vader gargoyle, though he was difficult to see because he was so high up.