e Carnegie Mellon Human-Computer Interaction Institute. Hudson admits, however, that he's not yet sure how well the technology will work with people in other types of jobs, as well as consumers. "I suspect that something slightly different will be needed, particularly for task-oriented workers," he says. Fogarty and Hudson believe their technology could provide benefits beyond basic voice call convenience. The system could, for example, prioritize incoming instant messages based on the user's current activity-sending crit- ical messages through immediately, delaying others to a more convenient time, and jettisoning spam. "Quite simple sensors will do the job," says Hudson. The researchers first plan to integrate the technology into a computer-based instant messaging system. If that implementation proves successful, they will next target landline and wireless phones. "There's no technological roadblock that would prevent this technology from being deployed within a couple of years," says Hudson. The researchers' ultimate goal is really quite simple, says Hudson. "We're out to prove that mother was right: it's not polite to interrupt while someone else is talking." 1.7 E-MAIL LEADS TO INSTANT MESSAGING E-mail is a dominant data communications service, although its future is becoming less certain, due to rising spam and instant messaging usage. With more than 500 million business E-mail users worldwide today and over 20 ON THE MENU-TELECOM SERVICES billion spam messages expected to be sent daily worldwide by 2006, accord- ing to IDC statistics, the impact on business communications is huge. IDC estimates that spam represents 32 percent of all external and internal e-mail sent on an average day in North America in 2003, up from 24 percent in 2002. The rising torrents of spam are reducing e-mail's usefulness by forcing users and IT staff to expend additional time and energy to identify, delete, and prevent spam from clogging in boxes. "To keep e-mail at the collaboration center stage, e-mail proponents will need to do