Sirius XM Radio will launch an application for the Apple iPhone today (6/ 18) that will bring the satellite radio service to iPhone and iPod Touch users. The service will be free for those who subscribe to Sirius’ Internet service, others will have to pay about $3.00 per month. Sirius currently has about 19 million subscribers, most of which signed on when buying cars that had the necessary equipment built in to a newly purchased vehicle. While Sirius faces tough competition from free radio services on the iPod like Pandora and Slacker, the company will gain access to a substantial portion of the more than 40 million devices sold by Apple to date.