Mynonymouse sez, "The Library of Congress just posted a Flickr set of lovely WPA posters. There are awesome ones about keeping your teeth clean, science and one that seems to be about drunk driving but also might warn of a previously unknown deadly reactive incompatibility between gas and whiskey."
These are awesome designs, but it's a disappointment that the LoC posted them at such crummy low-resolutions. The nation's treasures deserve better than that.
Update: See the comments for lots of places where you can get higher rez ones.
I write books. My latest is a YA science fiction novel called Homeland (it's the sequel to Little Brother). More books: Rapture of the Nerds (a novel, with Charlie Stross); With a Little Help (short stories); and The Great Big Beautiful Tomorrow (novella and nonfic). I speak all over the place and I tweet and tumble, too.