I just love these! Phil Bradley has used the magic of Paintshop Pro and Photoshop to modify World War I and World War II posters to have a save libraries message.
You can see the whole set on Flickr.
A couple of weeks ago he put together some very witty save libraries themed bumper stickers, my favorite being
Libraries; more precious than the Ring.
Libraries; tastier than 2 hobbits breakfasts.
Libraries; more trustworthy than the Fellowship