Using today’s videoconferencing technology to link more than three or four remote sites can be prohibitively expensive. But physicists from Caltech have devised a method that enables people located at as many as 40 sites around the world to confer affordably. The new setup employs a network of servers, scattered across 27 countries, that brings people together from different sites in one “virtual room” on the Internet. This approach eliminates the expensive hardware at each site that conventional systems require; instead, it can use cheap commercial webcams and microphones. It should thus allow some users to join videoconferences who couldn’t afford to otherwise. A user simply downloads software written by the Caltech group and logs in to a Web site; each of the other attendees appears in a separate window on the user’s desktop. More than 5,000 scientists from 88 countries are already using the system, which a team led by Harvey Newman and Philippe Galvez originally developed as a means of communicating with colleagues. The researchers have recently started up a company, VRVS Global in Pasadena, CA, to commercialize the technology.