Opentape
http://opentape.fm
Add a feed, and you've got a podcast. "Opentape is a free, open-source package that lets you make and host your own mixtapes on the web. Upload songs (via web or FTP), reorder, rename, customize the style, and share what you like on other sites with an embeddable player."
Muxtape
http://muxtape.com
"By uploading a song you agree that you have permission to let Muxtape use it."