The developer of the shell-fm software just gave me a clue as to why it is so painful to
try to play anything through stdin with mplayer: apparently mplayer does aggressive
caching and won't start playing until it gets some large amount of input first.
shell-fm has an "extern" function that'll fork off a process to play through
an external player, but it won't work because mplayer is expecting to grab quite a bit
of the stream.
-ken