When I ride my bike, I like to listen to music. I don't do this when I am in a group ride or when I am on the road, but I definitely listen to music when riding on the trails and on my trainer. It doesn't matter how often I update my music, I eventually get tired of listening to my own library.
Last year I started using Pandora on my iPhone; however, I have not been able to create the perfect "station" for training sessions. This shouldn't be a problem anymore. Pandora has announced a collection of workout stations. I am listening to the "Alternative Endurance Station" right now and it is pretty good. (I just hope that "Train in Vain" by the Clash is not foreshadowing my results for next season.)