This deal has ended.
AllPosters has a coupon (use code 12HOURS) for 30% off valid through 11pm EST 12/20 and is able to ship overnight through 11am 12/21 (though the code won't last that long). AllPosters carries 300,000 posters and prints at very good prices. They also do great framing (perfect for gifts) and their vintage posters are always worth a look. AllPosters has added a ton of posters and prints to their sale section and now has over 21,000 items on sale.