If you want to make a day of it, hit Riverby Books in Fredericksburg, Va., a little over an hour from here in good traffic. Very cool place. They have a DC location, but I haven't been to it. Here's the F'burg link: http://www.riverbybooks.com/
Diana S. replied:
Also found : Riverby Books www.riverbybooks.com 417 East Capitol St SE, Washington (202) 543-4342 Lantern Bryn Mawr Bookshop www.his.com 3241 P St NW, Washington (202) 333-3222