Amazon Cloud Player for Android is pretty nice. You can upload 5GB for free (I am uploading 695 songs) and can play them on our Android devices for free (via Amazon Cloud Service). I am playing my songs on my HTC EVO and Xoom. Obviously you have to have an Amazon account. I do, so I am trying it out.
Amazon Cloud Player goes live, streams music on your computer and Android -- Engadget
Amazon.com: Online Shopping for Electronics, Apparel, Computers, Books, DVDs & more
Amazon Cloud Player goes live, streams music on your computer and Android -- Engadget
Amazon.com: Online Shopping for Electronics, Apparel, Computers, Books, DVDs & more