Slacker don’t just make an mp3 player, it’s also wifi enabled to play internet radio. The catch is that the stations are streamed from the slacker server but you can also create your personal station with your choice of music. The stations you saved on to the player is also cached so when there’s no wifi it’ll still keep playing music. There is a 4gb or 8gb version and can store enough music for many hours. Check it out here.