Napster fans are wearing their MP3-lovin’ hearts on their sleeves. Pro-Napster T-shirts are popping up on eBay, while rock band the Offspring is selling ”napster…good” tees on its website (proceeds go to charity). And it’s not just a Web thing. In a Greenport, N.Y., movie theater ”Napster Rocks/Metallica Rots/MP3 Forever” shirts are sold alongside movie munchies. Nothing like a little social protest with your jujubes.