While demand is low, & legal issues seem clear, hop on to this nice on-demand music service: Deezer
You can take your Pandora or Last.fm favorites, & just add them to your playlist, available any time. That’s On-Demand. And you can upload your own music, which will be shared with everyone if Deezer has the license for it, or just with yourself otherwise. The interface is Flash based & intuitive. The only thing missing is the old Web thing called: URI – you can’t link directly to any resource.
Highly valuable stuff. Thanks Deezer!
Update: in the new version, it is possible to link directly to songs. E.g., the mathematician’s hello hammerheads