IT'S A DIRTY JOB, BUT SOMEONE HAD TO exhort the graduates of Kings-wood Regional High in Wolfeboro, N.H. This year, by unanimous vote, the 115 graduating seniors chose—a big janitor-in-a-drumroll, please—the school's two custodians, Bob Rivera, 36, and Peter Yates, 33, to deliver the June commencement address.

"We ran off a couple of names," explains student rep Harry Cummings, 18. "Someone yelled, 'How about Bob and Pete?' There was a silence—and then everyone cheered."

"We have a rapport with the kids," says the Buffalo-born Yates, who, along with Rivera, a native of Boston, knows every student in the class by name. "We're like the big brothers in a big family." Yates and Rivera have nurtured the relationship by lending a sympathetic ear to student problems—and even helping out with pranks like booby-trapping lockers with confetti bombs.

But on the podium, the speakers turned serious. Yates concluded his remarks by quoting the poet Kahlil Gibran: "Farewell to you and the youth I have spent with you...." And Rivera urged them: "Do not follow where the path may lead, go instead where there is no path and leave a trail."

Yet an hour after their standing ovations, Bob and Pete were back at the scene, sleeves rolled up. There was a stage to dismantle and a sound system to break down. "We're probably the only commencement speakers in history," says Rivera, "who've had to clean up after themselves."