In Melee, run turnaround animations are extremely slow and irrelevant in the meta. However, if you turn around on the very edge, the animation gets sped up a bit as you regain momentum. 

https://media.giphy.com/media/mTivQvX3ZpcRi/giphy.gif

This tech is pretty much like moonwalking; you gain momentum and propel yourself backward in the air, except you can do it with characters that have bad or impractical moonwalking abilities (or if you just can't moonwalk at all). You could possibly do some extreme mindgames with this due to how far and how fast it shoots.

Distances:

#1. Yoshi/Mewtwo

#3. Pikachu/Pichu

#5 Kirby

#6Doc/Mario

#8 Young Link

#9 Sheik/Falcon

#11 Ice Climbers/Link

#13 Fox

The rest of the cast gets insignificant distances, however Ganon can autocancel his B-Air, some characters may also be able to ledge cancel.