I'm really astounded by the general unusability of these services. (And I would also add Odeo AND Evoca to the heap of junk.)

Being a radio-savvy person (work done at commercial stations) I thought that I can easily compile a playlist of
- my voice recorded,
- songs hosted by others,
- songs uploaded by myself
and I can incorporate a player into my site. (No downloads allowed, no copyright infringement paranoia.)

None of the above mentioned services could fulfill me. Any ideas?

Have you tried garageband.com? I don't think it will do quite what you want, but it may be the closest (of the services I've seen).

I believe Garageband will help you make a podcast using other music on the site, your own music, and your own voice.

I haven't tried it myself, so I can't testify to its usability. I wouldn't be surprised if you found similarly awkward to the other services you've tried.

This is where Apple has its advantage with the iTunes/iPod/iTunes Music Store combination. By controlling the hardware, the software and the online environment, they have a much better chance of getting everything to work together seamlessly. The service providers who just have an online environment plus possibly a client download have a much harder time of integrating with third party hardware and services.

Cheers, I'm checking it up.