Apple has launched a new billboard campaign featuring the iPad in a number of cities across the globe. As AppleInsider first reported, the billboards began appearing in San Francisco last week. I've also seen them dotted about London. The billboards show a combination of three iPads and iPad minis and various apps displayed on each. Every billboard has a different theme. For example, one billboard shows apps related to art, while another shows apps related to fashion, and another, music.New billboard campaign touts variety of iPad apps