Quick experiment I did using a polarised camera lens filter: looking at a CRT screen and an LCD screen and proving that the light from a LCD screen is polarised (which is a side-effect of the way that they work).
This link was originally posted to /r/Experimentally. See more things from Dan's Reddit account.
The original link was: https://www.youtube.com/watch?v=GwzUMEuGZHs