I just discovered Pandora this morning when reading TechCrunch, but I'm already wondering why it took this long to show up. Pandora is an idea so simple, and yet so amazing, it is incredible that it took this long to come out.
To try and explain it would be a disservice to Pandora. What each of you need to do is go over to Pandora and enter in a song or artist you like, than just continue working while Pandora operates in the background. After you realize you've been listening to great music you've never heard before, stop, go here and pay these genius' the reward they are due.
I know it may sound like I'm paid to plug their service, but honestly, not since the iPod has a product changed the way I listen to music so dramatically.