So is it possible to stream music to the Rio Receiver if they are on different IP networks? I'd like to put the free receiver in my office and be able to access my music at home.

I think you would have to configure the routers that are inbetween the two networks to do IP forwarding in order to do that.

What connection speed do you have at home to stream stuff outbound? I hope it's a T1, Because most DSL connections top out at about 384k, which is barely enough to stream a full-quality MP3 if there were no other overhead.