Looks like the key is using this:
https://addons.mozilla.org/en-US/firefox/addon/446

to pry the content out of the page and into a media player of choice.

Windows Media is at version 10 on Windows, was stopped after version 9 on Mac, and seems to have no options on Linux:
http://www.microsoft.com/windows/windowsmedia/player/10/readme.aspx#System
http://www.microsoft.com/windows/windowsmedia/player/9series/sysreq.aspx
http://www.microsoft.com/windows/windowsmedia/player/mac/default.aspx

Maybe their mobile video service would be more ecumenical…?
http://mlb.mlb.com/mobile/video.jsp

jd/adobe

I subscribed to MLB.TV 3-4 years ago when I lived in San Diego & wanted to keep in touch with my beloved Giants.

While I was very impressed with the quality and convenience — I will warn you that (unless they’ve changed the policy) not every game is televised through it. On any given night, it seemed that only 85% of the games were available. So you were SOL 1-2 times out of every 10 and usually on Saturday due to the Fox game of the week. I am not sure how the broadcast blackout rules were applied.

The interesting thing is that slingbox wouldn’t help your situation because (I’m assuming) you’re a red Sox fan living with Colorado cable. What someone in your situation would need to find is a slingbox owner in Boston metro who is willing to share their slingbox server access info with you. If it hasn’t happened already, I suspect that “slingbox swapping clubs” will start popping up to connect ex-pats in Boston & Colorado & Seattle & Atlanta so they can follow their local teams/weather/news.

Note: I do not condone this action. I do not think that individuals should work around the rules just because technology gives them the ability to. OTOH, I believe that it is in content owners best interest to recognize what is possible technically — and instead of resorting to litigation or DRM — provide their assets in the most convenient, affordable and compelling method to consumers. See CD/Napster/EMusic/iTunes discussions …