Isn't this the third case of odd smells reported recently? One in LA, one in Seattle I think??
Very bizzare, how can a smell come and go and nobody can figure out what it is?
I believe you can add the DC area to the list of odd odors, and around the time Hurricane Rita hit, a few Freepers in the Dallas area were commenting on a strange odor in the area. (This was on the long Hurricane Rita thread.) The Freepers were speculating that the winds were somehow bringing foul odors up from New Orleans, but I really doubt that.
(I live in the DFW area and actually went outside myself to check it out when the Freepers were talking about this, but could not detect any strange odors.)