It combines the efforts of a bunch of fandoms, including my fellow Joss Whedon fans (like electrcspacegrl, who brought the site to my attention).
I've heard of a lot of heartening action on behalf of the writers: Whedon fans delivering pizza to strikers, Drew Carey doing the same thing at CBS Television City, Jon Stewart financially helping staffers on The Daily Show and The Colbert Report, actors from shows ranging from Grey's Anatomy to Reno 911! joining the picket lines in costume, and Steve Carell's unique way of honoring the strike. Remember, folks: no one wants to go on strike; people go on strike if they feel they have no choice. This is affecting writers I'm acquainted with; they'd much rather not be on strike. So I wish them luck with reaching a settlement quickly.
Oh, and TV and comic writer Mark Evanier is an especially good resource for strike news.