SoundCloud

SoundCloud kicks ass. Period.
 
Their sound distribution service is really simple, fast, reliable, and even pretty. It's expensive, but so much refreshing compared to the rest that you'll want to pay once you've tried it. Looks like Streams of Europe's upcoming tracks (and even older tracks) will use their widgets a lot.
 
Thanks to Alden, who embed a SoundCloud DropBox in his blog (and who was the first complete stranger to write something about Streams of Europe).