I made some modifications, to support both normal lists and m3u files.
I added conditional statements which recognize a new GET parameter "filetype". If it is there, and its value is "m3u", then a .m3u file is generated.
filelist.tpl
{.if|{.=|{.urlvar|filetype.}|m3u.}|#EXTM3U.}
%files%
[style]
[files]
{.if|{.=|{.urlvar|filetype.}|m3u.}|{:{.mime|audio/x-mpegurl.}:}.}
%list%
[file]
%item-url%
[folder]
%item-name%/
Then in the hfs.tpl add a line like this in the menu's div. I used it right after the normal File list.
hfs.tpl
<li class="last"><a href="{.get|url|tpl=list|filetype=m3u|folders-filter=\|recursive.}">File list (.M3U)</a></li>
Enjoy!
Mijo