For me, i didnt unplug the peripherals,
i wirelessly unplugged their computer
with something very simular to this:
http://www.intermatic.com/?action=prod&pid=9343
finnally after turning them off 6 or 7 times,
they finnally looked down and saw it, after reading what it was
on the back sticker, he stood up and said "whos doing it!"
the teacher put it in his desk, so i stole it back out when he went to lunch
and by the way, this is the mouse you should have bought dude,
http://www.ucam.org/chat/signed/stupid.jpeg
that'll come in handy