Flip YouTube videos horizontally.
Just replace "youtube.com" with "mirrorthevideo.com" in the URL. Here's an example.
When two people are facing eachother, everything is on the opposite side. When they move to your right, they're actually moving to their left. This is confusing if you're trying to copy the other person's movements, such as in a dance tutorial.
Mirroring the video avoids this problem. Their left is the same as your left, so it's much easier to immitate their movements.
Cranked out by Tom Dalling