I'm not trying to sell their products, but the Humane Society has some cool t-shirts with the "Chimps Deserve Better" motto. I'm sorely tempted to get the ringer tee, although I can only imagine the looks I would get.
As I grow older, I'm feeling more "in your face" about animal issues. I know that's not "diplomatic" or "strategic," but I get so tired of that crap.
Anyway, check out the other humane gear on the site. Some of this stuff is pretty clever.