There's tons of stuff all over the SJGames website. There's
Wallpapers and
Logos available, there's the
GURPS Fourth Edition Logo located at the top of the main
GURPS Page, and every
GURPS Book has a cover linked from it's description page which could be printed out (such as the Basic Set
Characters and
Campaigns covers). As for Propaganda to show people, there's all the free material from
e23, not to mention the book descriptions from each books page.