"Witches," says Joe Trippi. "And it pisses me off because they have people all over the world." Trippi, the fiery campaign manager for Howard Dean, is talking about Meetup.com, the year-old Internet service created to facilitate gatherings of people who share common interests—everything from knitting to Wicca—that is now the primary grassroots organizing tool for Dean. Trippi obsessively tracks the latest Meetup figures, and he has just learned that the number of registered Dean supporters has surpassed 25,000, far more than the next largest Meetup group, witches, who trail Dean by 10,000 but whose stats still irk Trippi a little bit. "They get their numbers all revved up because they get lots of people in London and Paris or whatever."