I don't know if this counts, but I pretty much use Slacker exclusively (not many other options for a Canadian). The nice thing though is that I was able to get 6gb of data for almost nothing, thanks to a recent retention deal. AND, my truck is Bluetooth equipped. So I have the thing mounted on my dash, with a car charger, and have access to basically unlimited streaming audio, it's really really cool. In terms of my own collection, I just have it stored on 64GB USB drive that I have plugged into my deck. I don't even keep music on my phone, I think I have 1 song on there that I used for testing (Foo Fighters, FYI).