Before you skip this because it’s “another Portal video”, know also that it has a healthy amount of real physics, unportalable curtains, and a man throwing a cap. Also, a lesson on funding research.
This video by James Craft & Co. managed to make the CG effects for the portals look right at home — not too brightly neon that it looks fake, and not just like an elliptical fluorescent tube. And although James apologized for the story, I think he made a seminal video on the dangers of poorly managed research funds.
Moral of the story: Develop Long Fall Boots before testing infinite loops.
You’re welcome, Cave Johnson.