As a 30-something long removed from school, I never got to experience the presumed joy of seeing, firsthand, some underpaid, overworked, beleaguered teacher go Howard Beale on a student's cell phone after it went off during class.

I can't bemoan bad technological timing, though, since the same progress that allowed cell phones to be ubiquitous permitted me to see teachers around the world get pissed off on YouTube. The yin and the yang. With high school and colleges recently starting up again, I present a few good examples for putting the phone on vibrate.

If we learned anything from 'City of God,' it's that you don't piss off Brazilians. This scene from a Brazilian school plays out like a mini-horror movie, with the viewer expecting the (phone) murder the first time it rings, only to get the nice, delayed shock. Dude let you slide the first time, my young friend. Why would you tempt fate again? (NSFW if you know Portuguese.)

This student's phone goes off while the teacher is telling the class to turn off all phones before a test. He received an A in Ironic Studies. Less so for the test. (NSFW, contains words you'd yell at your boss if you ever got the nerve to quit.)

Here, a young Seth Rogen pulls the fake-friendly "Hey man, it's cool. Can I see your phone for one second?" trick before demonstrating the power of gravity.

Are students really this stupid now? If you're going to talk on the phone in class, get to the back corner, man. Note to students: ducking your head while sitting in the first row is a little like putting on your seat belt after driving off the Grand Canyon.

This one is like a time-lapse video, with the teacher going through six months of feelings -- from frustration to bargaining to resignation to anger -- in seconds.