OK, maybe you're still a fan of Pandora, even though you probably realized after a week that it's playing you the same songs in pretty much the same order, and that its "music genome" engine thinks Lady Gaga sounds a lot like Nickelback.
Or you might prefer Hype Machine, which aggregates music from blogs that generally conform to the indie tastes of overly precious Pitchfork critics.
Shuffler combines elements of both services and comes up with something completely new and truly valuable. Basically you choose from among 120 genre-based channels that range from black metal to classical, post-rock to dubstep. Click on a favorite and it will play you a steady stream of music culled from blogs and sorted by actual humans with actual brains.
If a song doesn't interest you, hit the arrow to advance to the next one. If it does, you'll find the associated blog entry right on the same page. And since it will have been written by someone who's passionate about the artist, it's almost guaranteed to be more interesting than the warmed-over bios you'll find elsewhere.
I've only known about Shuffler for a couple of weeks, but I've already been introduced to more new and interesting music than I've discovered through Pandora and Hype Machine in the last year. Try it yourself and let us know what you think.