It was originally leaked in a company memo but Sirius XM released their iPhone application yesterday. Sirius XM for iPhone lets you listen to the online audio streams of Sirius XM’s combined range of programming on your iPhone, iPhone 3G, iPhone 3G S, or iPod touch.
The app itself will be free, but you’ll need to be a Sirius subscriber ($2.99) for it to work. Unfortunately, certain programming available for regular Sirius subscribers will not be available for Sirius XM for iPhone. Sirius XM Premium Online is available for download from within iTunes and comes with a free 7-day trial.