Mark your calendars for the National Geographic Warehouse sale, which is slated for November 20-22 at the D.C. Armory.
I went last year and bought several Christmas presents at a huge discount. You can find everything from maps and atlases to videos and jewelry, and this year there are framed prints of National Geographic photos available. There are also 300 book titles for sale.
Hours are 9 a.m.-5 p.m. each day and there's free admission. The Armory is located right next to the Stadium Armory Metro stop on the blue and orange lines.