Icecast (OSS implementation of ShoutCast) is the only thing I'm
familiar with, and even that's been ages. My roommate and I used to do
something similar with a USB FM radio tuner, pumping the output over
Icecast (private). At the time my roommate worked 2 floors
underground, and my own office got terrible radio reception. Later I
switched my setup from streaming to just recording, with cron jobs
tuning the radio and starting and stopping the recordings. The
resulting MP3s were dropped into a web accessible directory and a PHP
script generated a RSS feed to be pick up the recordings as podcasts.
Official podcasts and streams have made the whole setup obsolete.

http://en.wikipedia.org/wiki/List_of_streaming_media_systems might be
helpful if you're looking for something other than Icecast.

FYI, MLB streams audio for all it's games to MLB At Bat smartphone
apps, no blackouts. Used to be $15 per season for the app, but this
year they had a free version and an in app purchase for the full
version. Not sure if you get the audio streams on the free version,
and you may be able to find the streams online at MLB.tv as well.

--
Andrew Zbikowski
http://andy.zibnet.us/
I reject your reality and substitute my own.