I've heard about Spotify since its launch, and it's rumored to be the Pandora-killer. As quoted below, it's "a magical version of iTunes in which you’ve already bought every song in the world".
The differences between tiers - Unlimited is better quality, has an offline mode, and allows full cell phone access. And you need to sign up for an invite to access the free version - which I've done, so we'll see.
Yes, I just did a Louie Louie show a few weeks ago, but I needed some inspiration for a theme this week - and it didn't help that I spent my Memorial Day watching reruns of Deadliest Catch. NonDescript, Tuesdays, 9am-10am PDT (12pm-1pm EDT)