After looking around a little more, I realized that there is an XM Receiver for the PC for only $50. The device connects to usb. Fortunately, it is a serial device that is simply using a FTDI serial-usb chip to convert the signal to USB. The pins to grab the serial from are here. We could just connect them up to a MAX232 chip and viola...serial to the empeg. Also there is a digital audio hack, so if Stu ever gets a digital input, we could run digital quality sattelite radio in our vehicles. There have already been GPL'd Perl modules written to interface with it, and I'd imagine that could be ported to C. I'll probably create a new post in the Projects section if anyone is interested.