AudioFeast is a broadcaster to MP3 players - essentially, a podcaster selling downloadable chunks of various genres of music. It doesn't offer native iPod support (thanks to Apple probably) - the list of 'officially supported' players is pretty small. Then again, it's MP3...so...uhh...
The whole thing is really quite strange. Check the technology page, for example.
Maybe a nice case study in how not to cement a first-mover advantage - they had roughly the podcast concept nailed in 02.