The first time I ever heard of I dosing was my freshman year here in Madison, when some stoner in my dorm ran up and down the hall screaming that "It worked." I never saw how a youtube video could affect someone like a drug, so I just assumed there was something else in that guy's cocktail of hallucinogens.
I found a few different kinds of i Dosing videos. Some were just still, abstract images or collections of images with trance or techno music in the background. Others were completely black screens with a series of tones. The most interesting kind I found was a pattern of flashing lights which would mess with your peripheral vision, similar to the Guitar Hero effect. After about two minutes of staring at the screen and then looking away, my walls appeared to be breathing for a few seconds.
For many of us, parental concern about i Dosing may seem like over-protection. We are at an age when we know something coming from a computer isn't going to get us high. If I were a parent, however, and I found out my kid was looking into i Dosing, I might be a little concerned - not because I would worry they would get high from it, but because it may mean they are looking for something that will alter their state of mind, which may lead to other things.