I went to a neat exhibit called "Roads of Arabia" at the Sackler Gallery. It's probably worth a visit and it's a pretty easily/quickly digestible exhibit. Really interesting artifacts from civilizations that apparently don't have publicists as good as those of the Egyptians or Romans and are less-standard museum fare. I brought only my iPhone, so my pictures aren't great (but I later learned I wasn't allowed to take them anyway so at least it's something):
Side note: also went to a cool exhibit of Chinese activist/artist Ai Wei Wei at the Hirshhorn. I'd already seen most of the stuff online, but neat to see it in person.