What are we listening to?

I am confused by the HD-2 commercials:

…. the on the hour commercials that say "I cannot hear HD unless I have an HD radio device."

I am confused, because I am listening to it on my computer and thinking I am listening to HD radio. But then, since it is never stated in the commercial that I could listen to HD radio on my computer, at home, at the office, when traveling and have 3G or WIFI etc access, using my computer, I assume I am NOT listening to HD radio but just the average old stream. ??

Am I listening to HD radio on my computer even tho it is inferred that I am not?

Am I listening to HD radio when I use my iPhone 3G using "Tuner.app" and listening either on (via) a WIFI or 3G to one of Tuner's 500 pre- tuned stations, plus the ones that are iTunes capable that I add to the mix?

Do I really need a separate stand alone HD piece of hardware, another device, to listen to HD radio to hear more than I'm hearing with a computer device instead of an HD radio receiver device? I always have my computer with me, and generally always plugged into the Internet, but I'm not about to lug a desktop radio along for the ride.

--Jerry in Phoenix, Arizona

[Program Director John Hingsbergen: "Jerry in Phoenix, and other listeners, are listening to a web stream of an HD Radio station. His comments, perhaps tongue-in-cheek, are on the mark that the way we access “radio programming” is changing. We at WMUB encourage our listeners to tune in, whatever way you can."]