[QUOTE=MrAOK
If you are willing to give up non stop, I believe the choices turn into American (thru chicago), Northwest (which flies some nonstops from minneapolis to dca) and one screwy one -- Alaska Air has one of the few long nonstops to dca (from seattle).
.[/QUOTE]

you forgot about hp. sorry to keep mentioning it, but i've never once found another airline in the same ballpark for last minute purchases and their total travel times are absolutely unparallelled (with the exception of ua from iad, which operates the ONLY nonstop in the market).

ps - i don't have any particular loyalties or interests in hp. it's just that this thread echos my current situation exactly so i've done quite a bit of "research" on the topic.