BYOP(illow) to Pittsburgh’s annual Giant Pillow Fight! The fight, what organizers call “people asserting their right to carry pillows,” starts with a mystery signal at 8 p.m. For 15 minutes, you can (gently) whack your loved ones with a (preferably soft) pillow. Just don’t be a jag about it! After the fight, stick around for a screening of How To Train Your Dragon.