Pink Shirt Day stems from this story of two boys from Cambridge, NS who started the campaign in support of a fellow classmate who was bullied for wearing a pink shirt to school. The movement is apparently growing all over the world now, something I didn't know until pegkerr posted the link in her LJ.
So, yeah. Go search your closets or make a trip to the local thrift store and get yourself a pink shirt. You still have a couple of days to do it. IT'S IMPORTANT, GUYS.
Oh, yeah, and the Facebook group is here.