The National Archives is hosting a gorgeous online gallery of British propaganda from World War 2. Although the usual war effort posters are well represented (usually featuring golden haired maidens with meaty forearms standing against a rising sun, which seems to be a universal propaganda image, regardless of side or cause), the comic illustrations are particularly gorgeous.
The image to the right is from Fritz and the Nazi Bomber... I love the demonic fire bomb in the background laughing and strecthing out its vaporous arms of flame.
The Art of War [National Archives]