Oke.. this is damn cool.
del.icio.us has implemented a schema of system tags. if you post a link to a file of a certian filetype, del.icio.us will automaticly add a system tag, like the one featured above: system:media:audio
If the system tag is for an audio file, calling a url like the one above, results in an RSS feed that will add the linked-to mp3 or wav file as an enclosure in the rss feed.
This basicly means that by simply adding a link to an mp3 to your delicious account, you have an rss feed with enclosures automaticly: a podcast feed.
I was clued into this via this post: