man, you know one of those electro-ab-exercise machines? You know, the ones that stimulate your muscles by sending electronic signals. Those thing HURT like hell when you wrap that stuff around your arm and put it to maximum power. Well, apparently, my roommate once wrapped it around my arm, and put it to full power in an attempt to wake me up.
My arm was flailing everywhere, but he told me that I was still sound asleep, oblivious to my flailing arm. I've put that ab-machine on my arm once and it really hurts like hell. I couldn't believe I wasn't able to wake up from it. Then again, I'm assuming that that stuff doesn't isn't very effective since your brain is wired in a way that makes involuntary contractions something that is not worth waking up for.