Just found out that del.icio.us automatically tags certain file extensions with tags like system:media:audio and generates RSS feeds with enclosures (like http://del.icio.us/rss/tag/system:media:audio).

Combined with an RSS-aware media player like DTV, this makes for a cheap way to create your own TV channel.

One of my current projects requires similar technology - this will be useful for testing, at least.