I have updated various pages on the Wikimania wiki, with specifics like directions from the airport:

http://wikimania2012.wikimedia.org/wiki/Dupont_Circle_Hotel

http://wikimania2012.wikimedia.org/wiki/Hostelling_International

http://wikimania2012.wikimedia.org/wiki/Washington,_D.C./Where_to_Eat%3F

http://wikimania2012.wikimedia.org/wiki/Washington,_D.C./Where_to_Drink%3F

I can do a page for the State Plaza and are there any other particular requests for info?

Cheers, Katie