Yesterday I chaperoned a group of ten year-olds to the Smithsonian. As the bus rolled by, I pointed out the Federal Reserve to my kid and one of the other boys his eyes all aglow said "ooohh, that's where Ben Bernanke works!" Even taking into account the possible uber-nerdiness of the group, this was a surprise.
On another note, five years ago (!) I pointed to a sign at the Smithsonian warning of another ice age and recent global cooling – well the sign (or something like it) is still there only now it does have a little placard above saying that this exhibit will soon be changed to reflect more recent science.