Photolibrary's current print campaign, Unlimited Use Royalty Free Images, has a new viral online component: theworldsbiggestad.com. Launched last week, the Web site invites users to help create the world's biggest ad by using a Flash-based interface to play with images and submit portions of the Photolibrary ad. The site was developed by TBWA Signapore, the agency that created the print campaign.