David
If you have an iPod Touch or iPhone, you can use the SimplifyMedia application along with the client app on your Mac or PC running iTunes. Then you can stream to your Touch or iPhone.

I have it running on my Mac Mini. I can then stream via EDGE, Wifi or 3G to my iPhone and have access to over 80 GB of music. Granted it won't do the DRM'ed music but all the MP3's work.