Billboards have to be creative to steal your attention. Forget an ironic turn of phrase or some smart placement, Carlsberg went right for our hearts (and guts) with free beer. Yup, this poster, which when up in London this week, allowed passersby to stop for a pint. The billboard was created by advertising agency Fold7 and Mission Media, and it was overlooked by a security guard. In big, bold letters, it championed itself as “Probably the best poster in the world.” We can’t argue that.