After a day at the beach, getting the tops of my feet sunburned, I came home and registered brainal.org (think Brainal Sex), and then found myself building a very strange website on it. <3 PHP.
Maybe you could use $_SERVER['PATH_INFO'] for the filenames. Your URIs would look like brainal.org/playlist.php/playlist....and the browsers would say they download playlist.m3u instead of playlist.php. b4n
thx, done :)