The wireless rollout at American University is especially ambitious, because it integrates cellphone coverage into a single data-delivery network that can deliver messages to laptops, handheld devices and telephones anywhere on the 84-acre campus. The university plans to stop offering traditional phone service in its dormitories eventually.

In any building, the wireless access ports are likely to be there, looking a little like the top half of a Lava Lamp, painted white and stuck upside-down to the ceiling.

The director of e-operations at the university, Carl Whitman, said being early to the wireless world created an advantage in attracting students who demand the latest technology and "becomes a plus for us."

Matthew Pittinsky, founder and chairman of Blackboard Inc., the large Internet education company that puts Professor Mallek's class materials online, said wireless access had "made higher education much more of a 24/7 educational environment than ever before," with instant access to classroom materials and research resources and a growing potential for collaborative study.

Mr. Pittinsky said the greatest power of wireless showed up in the dorm, the library and the commons. "There's less of an obvious use for wiring the classroom," where the benefits have to be balanced against the distraction, he said.

At American University, Professor Mallek said the benefits of the technology in his classroom far outweighed the problems. He ran the pilot project at the business school that helped the American decide to put in a campuswide network and said he had grown used to students' flipping their screens.

"It's a new type of social commentary, to hear clicking," he said. "It's an audible vote."

He suggested that it might even be making him a better teacher. He takes the threat of losing his students to e-mail and online newspapers as a challenge to keep lectures interesting and lively.

"As a professor," he said, "if you are not productively engaging them, they have other opportunities."

Mr. Whitman, the director of e-operations, said he was testing new programs that might address some of the problems of online distraction. A system that takes the locations of students into account could be used to set rules that varied from place to place. Any use of the Internet might be acceptable in the library or the dean's office, he said, "but if you're downstairs in Jay's classroom, you could not surf the Internet or you could surf the Internet but only go to CNN.com for in-class reading."

Joseph Sun, a first year M.B.A. student in Professor Mallek's class, takes notes with pen and paper. He owns a laptop but does not take it to class. Although it "comes in handy to look up an article or quote during discussion," Mr. Sun said, he has to resist "the temptation to surf the Net during lectures."

Students say they are finding a balance in the classroom between the good uses of online technology and its temptations. Tetse Ukueberuwa, a major in environmental studies at Dartmouth, said, "Over all, it's a great thing," being able to check e-mail messages and conduct online research anywhere on her campus.

Ms. Ukueberuwa said she preferred to take notes by hand, however, saying: "I feel I'm more in touch with what the teacher is saying. You're looking at the teacher instead of looking at your computer."

As a junior, though, she realizes that she may be "old-fashioned." Every incoming class, she said, seems "more technologically advanced" than the last.