I keep trying to wean myself from blogging about weird goings on in and around Golden Gate Park — but I found it hard to resist this one. I was walking through the Haight on Halloween and saw some guy asking people to smoke his thumb. Indeed, when I looked closely, I could see a plume of smoke rising up from beneath his thumb. One person actually stopped and smoked it, and then the guy started smoking his own thumb. Apparently he’d wedged a tiny, still-burning roach in there somewhere. Eventually it burned down and singed the inside of his finger. “Ow,” he said, and then the demonstration was over.