Years ago, students who wanted to plagiarize would at least have to consult a book. Cheating on a test required smuggling notes.

Nowadays, all it takes is Googling a few words to cut and paste together a term paper. With more tests being taken on a screen instead of in blue books, the temptation to look up answers on the Web can be strong.

But while technology has opened up new frontiers for cheaters, it has also given teachers new tools to stymie them.

"It's a little bit like a proliferation in arms races: Once things come up on one side, the kind of detection and awareness on the other side has to be elevated," said Ron Daniel, Virginia Tech's associate provost for undergraduate education.

Cheaters can use cellphones to call friends from the bathroom, and if their phones have cameras, they can take pictures of tests. So some schools, including Cal Poly Pomona, have banned cellphones in testing centers.

It's common for professors to Google strings of words that don't sound like they were written by a student.

Some professors have even written computer programs to root out plagiarism more efficiently.

Louis Bloomfield, a physics professor at the University of Virginia, posted his program on the Web for free download, which he said is done hundreds of times a month.

Software Secure of Cambridge, Mass., sells programs that prevent students from opening browser windows to cheat during electronic tests. The next level of protection it plans to offer is a webcam to ensure students don't cheat on distance-learning exams, said company President Douglas Winneg.

Gretchen Kotch, an assistant professor of math and computer science at Goucher College, recalled hearing the familiar pinging of instant messages during exams she monitored when she was a graduate student.

"You hope that your students have the ethics not to do such things," she said.

But many students apparently don't.

In a poll of college students released last year by the Center for Academic Integrity, 70 percent of respondents admitted to some cheating, and nearly a quarter admitted to "serious test cheating."