Just click here to view the music compatibility from Cnet. It really kills three birds with one stone...clicking on the icons across the top will give you reviews and misc data about 14 of the top music services available, clicking the icons along the side will give you reviews of many of the top MP3 players available, and the chart as a whole tells you which services will work with which players. Can't get much better than that!

Hope this helps,
John