Youtube a place to find a video of everything!

I often turn to youtube to find a short video for my class.  I sometimes have trouble figuring out the right keywords to get the video that I would like to view.  Sometimes "inappropriate" videos are shown.  I am trying to figure out how to find exactly what I am looking for without having to watch the videos that I don't need or want.  Another downside I have found is with the resolution of some of the videos especially when shown with an LCD projector.  Sound can also be a problem, as in the one shown below at the beginning of the video.  When trying to illustrate how elements bond, I found this one done by some high school  for a class project. This is one of my favorites.  The students usually want to make one of their own.  Maybe one day I will take them up on it and see what they can come up with.