Having one's head in the clouds has taken on new meaning as a Vapor Cigarette trend picks up popularity. It's called "cloud chasing," and its goal is to produce big, thick, white plumes of vapor.

Sarah Merriweather of San Diego took to vaping as a means to quit smoking. A couple of months later, she was doing it competitively. Merriweather became one of the first to join a now booming ...