When your looking for new places to visit on the internet this winter, I've got a great one for you, The Library of Congress. It's possibly the only time Congress and good image can be used in the same sentence.
If you love looking through classical photography, wpa posters and art, you can spend hours on this site, and best of all you can download many of the high res files, but for personal use only. Here's the link, as well as a couple of images I downloaded. http://www.loc.gov/pictures/
Top Image: Lithograph of Steam Powered Photography that processed and printed on the spot, Cincinnati, Ohio 1871. Bottom Image: WPA Cover of theatrical production, "No More Peace" by Ernest Toller at the Cincinnati Federal Theatre, 1937.