Wasn’t it just the other day that teachers confiscated cellphones and principals warned about oversharing on MySpace?

Now, Erin Olson, an English teacher in Sioux Rapids, Iowa, is among a small but growing cadre of educators trying to exploit Twitter-like technology to enhance classroom discussion. Last Friday, as some of her 11th graders read aloud from a poem called “To the Lady,” which ponders why bystanders do not intervene to stop injustice, others kept up a running commentary on their laptops.

The poet “says that people cried out and tried but nothing was done,” one student typed, her words posted in cyberspace.

“She is giving raw proof,” another student offered, “that we are slaves to our society.”

Instead of being a distraction — an electronic version of note-passing — the chatter echoed and fed into the main discourse, said Mrs. Olson, who monitored the stream and tried to absorb it into the lesson. She and others say social media, once kept outside the school door, can entice students who rarely raise a hand to express themselves via a medium they find as natural as breathing.