This is pretty cool, and I hate damn near everything. It’s an application for jailbroken iPhones (and iPod touches) called uXM that lets you listen to XM Satellite Radio. Yes, XM is reportedly working on a proper application to launch with the App Store, but that’ll cost you money. This uXM is free, provided you already subscribe to XM.
You can find it in the iSpazio repository, or add this line to your Installer.app: http://www.millardsoftware.com/iphone.xml I have no idea what the previous two sentences mean, having used the iPhone for, maybe, two minutes in total, but I sure as hell like the idea.
There’s also a Sirius version, uSirius, if you swing that way.