CBS (NYSE: CBS) seems to see a big market for itself on the iPhone… Days after releasing a TV.com iPhone application two more have been announced. CBS Interactive has launched a GameSpot website specifically for Apple’s iPhone and iPod touch, offering GameSpot reviews, news, blogs and exclusive video interviews. The site was developed by CBS Mobile and lets users filter content by gaming platform. Meanwhile, CBS subsidiary Showtime Networks has launched an application for iPhones and iPod Touches that will let voting members of the Academy of Television Arts and Sciences (ATAS) exclusively view full seasons of Showtime series on the devices—should they own one. The aim, of course, is to increase nominations for the Emmys. The app was developed by Transperam, and there’s also an online site.